Patch to version 0.4.0 (#257)

* uncomment test

* Add random test for logistic regression

* linting

* Bump version

* Add test for logistic regression

* linting

* initial commit

* final

* final-clean

* Bump to 0.4.0

* Fix linter

* cleanup

* Update CHANDELOG with breaking changes

* Update CHANDELOG date

* Add functional methods to DenseMatrix implementation

* linting

* add type declaration in test

* Fix Wasm tests failing

* linting

* fix tests

* linting

* Add type annotations on BBDTree constructor

* fix clippy

* fix clippy

* fix tests

* bump version

* run fmt. fix changelog

---------

Co-authored-by: Edmund Cape <edmund@Edmunds-MacBook-Pro.local>

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.4.0] - 2023-04-05
+
+## Added
+- WARNING: Breaking changes!
+- `DenseMatrix` constructor now returns `Result` to avoid user instantiating inconsistent rows/cols count. Their return values need to be unwrapped with `unwrap()`, see tests
+
 ## [0.3.0] - 2022-11-09 
 
 ## Added

Cargo.toml

@@ -2,7 +2,7 @@
 name = "smartcore"
 description = "Machine Learning in Rust."
 homepage = "https://smartcorelib.org"
-version = "0.3.2"
+version = "0.4.0"
 authors = ["smartcore Developers"]
 edition = "2021"
 license = "Apache-2.0"

src/algorithm/neighbour/bbd_tree.rs

@@ -40,11 +40,11 @@ impl BBDTreeNode {
 
 impl BBDTree {
     pub fn new<T: Number, M: Array2<T>>(data: &M) -> BBDTree {
-        let nodes = Vec::new();
+        let nodes: Vec<BBDTreeNode> = Vec::new();
 
         let (n, _) = data.shape();
 
-        let index = (0..n).collect::<Vec<_>>();
+        let index = (0..n).collect::<Vec<usize>>();
 
         let mut tree = BBDTree {
             nodes,
@@ -343,7 +343,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
 
         let tree = BBDTree::new(&data);
 

src/algorithm/neighbour/fastpair.rs

@@ -17,7 +17,7 @@
 ///     &[4.6, 3.1, 1.5, 0.2],
 ///     &[5.0, 3.6, 1.4, 0.2],
 ///     &[5.4, 3.9, 1.7, 0.4],
-/// ]);
+/// ]).unwrap();
 /// let fastpair = FastPair::new(&x);
 /// let closest_pair: PairwiseDistance<f64> = fastpair.unwrap().closest_pair();
 /// ```
@@ -271,7 +271,7 @@ mod tests_fastpair {
     fn dataset_has_at_least_three_points() {
         // Create a dataset which consists of only two points:
         // A(0.0, 0.0) and B(1.0, 1.0).
-        let dataset = DenseMatrix::<f64>::from_2d_array(&[&[0.0, 0.0], &[1.0, 1.0]]);
+        let dataset = DenseMatrix::<f64>::from_2d_array(&[&[0.0, 0.0], &[1.0, 1.0]]).unwrap();
 
         // We expect an error when we run `FastPair` on this dataset,
         // becuase `FastPair` currently only works on a minimum of 3
@@ -288,7 +288,7 @@ mod tests_fastpair {
 
     #[test]
     fn one_dimensional_dataset_minimal() {
-        let dataset = DenseMatrix::<f64>::from_2d_array(&[&[0.0], &[2.0], &[9.0]]);
+        let dataset = DenseMatrix::<f64>::from_2d_array(&[&[0.0], &[2.0], &[9.0]]).unwrap();
 
         let result = FastPair::new(&dataset);
         assert!(result.is_ok());
@@ -308,7 +308,8 @@ mod tests_fastpair {
 
     #[test]
     fn one_dimensional_dataset_2() {
-        let dataset = DenseMatrix::<f64>::from_2d_array(&[&[27.0], &[0.0], &[9.0], &[2.0]]);
+        let dataset =
+            DenseMatrix::<f64>::from_2d_array(&[&[27.0], &[0.0], &[9.0], &[2.0]]).unwrap();
 
         let result = FastPair::new(&dataset);
         assert!(result.is_ok());
@@ -343,7 +344,8 @@ mod tests_fastpair {
             &[6.9, 3.1, 4.9, 1.5],
             &[5.5, 2.3, 4.0, 1.3],
             &[6.5, 2.8, 4.6, 1.5],
-        ]);
+        ])
+        .unwrap();
         let fastpair = FastPair::new(&x);
         assert!(fastpair.is_ok());
 
@@ -516,7 +518,8 @@ mod tests_fastpair {
             &[6.9, 3.1, 4.9, 1.5],
             &[5.5, 2.3, 4.0, 1.3],
             &[6.5, 2.8, 4.6, 1.5],
-        ]);
+        ])
+        .unwrap();
         // compute
         let fastpair = FastPair::new(&x);
         assert!(fastpair.is_ok());
@@ -564,7 +567,8 @@ mod tests_fastpair {
             &[6.9, 3.1, 4.9, 1.5],
             &[5.5, 2.3, 4.0, 1.3],
             &[6.5, 2.8, 4.6, 1.5],
-        ]);
+        ])
+        .unwrap();
         // compute
         let fastpair = FastPair::new(&x);
         assert!(fastpair.is_ok());

src/cluster/dbscan.rs

@@ -442,7 +442,8 @@ mod tests {
             &[2.2, 1.2],
             &[1.8, 0.8],
             &[3.0, 5.0],
-        ]);
+        ])
+        .unwrap();
 
         let expected_labels = vec![1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 0];
 
@@ -487,7 +488,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
 
         let dbscan = DBSCAN::fit(&x, Default::default()).unwrap();
 

src/cluster/kmeans.rs

@@ -41,7 +41,7 @@
 //!            &[4.9, 2.4, 3.3, 1.0],
 //!            &[6.6, 2.9, 4.6, 1.3],
 //!            &[5.2, 2.7, 3.9, 1.4],
-//!            ]);
+//!            ]).unwrap();
 //!
 //! let kmeans = KMeans::fit(&x, KMeansParameters::default().with_k(2)).unwrap(); // Fit to data, 2 clusters
 //! let y_hat: Vec<u8> = kmeans.predict(&x).unwrap(); // use the same points for prediction
@@ -249,7 +249,7 @@ impl<TX: Number, TY: Number, X: Array2<TX>, Y: Array1<TY>> Predictor<X, Y>
 
 impl<TX: Number, TY: Number, X: Array2<TX>, Y: Array1<TY>> KMeans<TX, TY, X, Y> {
     /// Fit algorithm to _NxM_ matrix where _N_ is number of samples and _M_ is number of features.
-    /// * `data` - training instances to cluster    
+    /// * `data` - training instances to cluster
     /// * `parameters` - cluster parameters
     pub fn fit(data: &X, parameters: KMeansParameters) -> Result<KMeans<TX, TY, X, Y>, Failed> {
         let bbd = BBDTree::new(data);
@@ -424,7 +424,7 @@ mod tests {
     )]
     #[test]
     fn invalid_k() {
-        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
 
         assert!(KMeans::<i32, i32, DenseMatrix<i32>, Vec<i32>>::fit(
             &x,
@@ -492,7 +492,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
 
         let kmeans = KMeans::fit(&x, Default::default()).unwrap();
 
@@ -531,7 +532,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
 
         let kmeans: KMeans<f32, f32, DenseMatrix<f32>, Vec<f32>> =
             KMeans::fit(&x, Default::default()).unwrap();

src/decomposition/pca.rs

@@ -35,7 +35,7 @@
 //!                     &[4.9, 2.4, 3.3, 1.0],
 //!                     &[6.6, 2.9, 4.6, 1.3],
 //!                     &[5.2, 2.7, 3.9, 1.4],
-//!                     ]);
+//!                     ]).unwrap();
 //!
 //! let pca = PCA::fit(&iris, PCAParameters::default().with_n_components(2)).unwrap(); // Reduce number of features to 2
 //!
@@ -443,6 +443,7 @@ mod tests {
             &[2.6, 53.0, 66.0, 10.8],
             &[6.8, 161.0, 60.0, 15.6],
         ])
+        .unwrap()
     }
     #[cfg_attr(
         all(target_arch = "wasm32", not(target_os = "wasi")),
@@ -457,7 +458,8 @@ mod tests {
             &[0.9952, 0.0588],
             &[0.0463, 0.9769],
             &[0.0752, 0.2007],
-        ]);
+        ])
+        .unwrap();
 
         let pca = PCA::fit(&us_arrests, Default::default()).unwrap();
 
@@ -500,7 +502,8 @@ mod tests {
                 -0.974080592182491,
                 0.0723250196376097,
             ],
-        ]);
+        ])
+        .unwrap();
 
         let expected_projection = DenseMatrix::from_2d_array(&[
             &[-64.8022, -11.448, 2.4949, -2.4079],
@@ -553,7 +556,8 @@ mod tests {
             &[91.5446, -22.9529, 0.402, -0.7369],
             &[118.1763, 5.5076, 2.7113, -0.205],
             &[10.4345, -5.9245, 3.7944, 0.5179],
-        ]);
+        ])
+        .unwrap();
 
         let expected_eigenvalues: Vec<f64> = vec![
             343544.6277001563,
@@ -616,7 +620,8 @@ mod tests {
                 -0.0881962972508558,
                 -0.0096011588898465,
             ],
-        ]);
+        ])
+        .unwrap();
 
         let expected_projection = DenseMatrix::from_2d_array(&[
             &[0.9856, -1.1334, 0.4443, -0.1563],
@@ -669,7 +674,8 @@ mod tests {
             &[-2.1086, -1.4248, -0.1048, -0.1319],
             &[-2.0797, 0.6113, 0.1389, -0.1841],
             &[-0.6294, -0.321, 0.2407, 0.1667],
-        ]);
+        ])
+        .unwrap();
 
         let expected_eigenvalues: Vec<f64> = vec![
             2.480241579149493,
@@ -732,7 +738,7 @@ mod tests {
     //         &[4.9, 2.4, 3.3, 1.0],
     //         &[6.6, 2.9, 4.6, 1.3],
     //         &[5.2, 2.7, 3.9, 1.4],
-    //     ]);
+    //     ]).unwrap();
 
     //     let pca = PCA::fit(&iris, Default::default()).unwrap();
 

src/decomposition/svd.rs

@@ -32,7 +32,7 @@
 //!                     &[4.9, 2.4, 3.3, 1.0],
 //!                     &[6.6, 2.9, 4.6, 1.3],
 //!                     &[5.2, 2.7, 3.9, 1.4],
-//!                     ]);
+//!                     ]).unwrap();
 //!
 //! let svd = SVD::fit(&iris, SVDParameters::default().
 //!         with_n_components(2)).unwrap(); // Reduce number of features to 2
@@ -292,7 +292,8 @@ mod tests {
             &[5.7, 81.0, 39.0, 9.3],
             &[2.6, 53.0, 66.0, 10.8],
             &[6.8, 161.0, 60.0, 15.6],
-        ]);
+        ])
+        .unwrap();
 
         let expected = DenseMatrix::from_2d_array(&[
             &[243.54655757, -18.76673788],
@@ -300,7 +301,8 @@ mod tests {
             &[305.93972467, -15.39087376],
             &[197.28420365, -11.66808306],
             &[293.43187394, 1.91163633],
-        ]);
+        ])
+        .unwrap();
         let svd = SVD::fit(&x, Default::default()).unwrap();
 
         let x_transformed = svd.transform(&x).unwrap();
@@ -341,7 +343,7 @@ mod tests {
     //         &[4.9, 2.4, 3.3, 1.0],
     //         &[6.6, 2.9, 4.6, 1.3],
     //         &[5.2, 2.7, 3.9, 1.4],
-    //     ]);
+    //     ]).unwrap();
 
     //     let svd = SVD::fit(&iris, Default::default()).unwrap();
 

src/ensemble/random_forest_classifier.rs

@@ -33,7 +33,7 @@
 //!              &[4.9, 2.4, 3.3, 1.0],
 //!              &[6.6, 2.9, 4.6, 1.3],
 //!              &[5.2, 2.7, 3.9, 1.4],
-//!         ]);
+//!         ]).unwrap();
 //! let y = vec![
 //!              0, 0, 0, 0, 0, 0, 0, 0,
 //!              1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@@ -660,7 +660,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
         let y = vec![0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 
         let classifier = RandomForestClassifier::fit(
@@ -733,7 +734,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
         let y = vec![0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 
         let classifier = RandomForestClassifier::fit(
@@ -786,7 +788,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
         let y = vec![0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 
         let forest = RandomForestClassifier::fit(&x, &y, Default::default()).unwrap();

src/ensemble/random_forest_regressor.rs

@@ -29,7 +29,7 @@
 //!             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
 //!             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
 //!             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-//!         ]);
+//!         ]).unwrap();
 //! let y = vec![
 //!             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2,
 //!             104.6, 108.4, 110.8, 112.6, 114.2, 115.7, 116.9
@@ -574,7 +574,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
         let y = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
             114.2, 115.7, 116.9,
@@ -648,7 +649,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
         let y = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
             114.2, 115.7, 116.9,
@@ -702,7 +704,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
         let y = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
             114.2, 115.7, 116.9,

src/error/mod.rs

@@ -32,6 +32,8 @@ pub enum FailedError {
     SolutionFailed,
     /// Error in input parameters
     ParametersError,
+    /// Invalid state error (should never happen)
+    InvalidStateError,
 }
 
 impl Failed {
@@ -64,6 +66,22 @@ impl Failed {
         }
     }
 
+    /// new instance of `FailedError::ParametersError`
+    pub fn input(msg: &str) -> Self {
+        Failed {
+            err: FailedError::ParametersError,
+            msg: msg.to_string(),
+        }
+    }
+
+    /// new instance of `FailedError::InvalidStateError`
+    pub fn invalid_state(msg: &str) -> Self {
+        Failed {
+            err: FailedError::InvalidStateError,
+            msg: msg.to_string(),
+        }
+    }
+
     /// new instance of `err`
     pub fn because(err: FailedError, msg: &str) -> Self {
         Failed {
@@ -97,6 +115,7 @@ impl fmt::Display for FailedError {
             FailedError::DecompositionFailed => "Decomposition failed",
             FailedError::SolutionFailed => "Can't find solution",
             FailedError::ParametersError => "Error in input, check parameters",
+            FailedError::InvalidStateError => "Invalid state, this should never happen", // useful in development phase of lib
         };
         write!(f, "{failed_err_str}")
     }

src/lib.rs

@@ -64,7 +64,7 @@
 //!    &[3., 4.],
 //!    &[5., 6.],
 //!    &[7., 8.],
-//!    &[9., 10.]]);
+//!    &[9., 10.]]).unwrap();
 //! // Our classes are defined as a vector
 //! let y = vec![2, 2, 2, 3, 3];
 //!

src/linalg/basic/arrays.rs

@@ -1775,7 +1775,7 @@ mod tests {
 
     #[test]
     fn test_xa() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         assert_eq!(vec![7, 8].xa(false, &a), vec![39, 54, 69]);
         assert_eq!(vec![7, 8, 9].xa(true, &a), vec![50, 122]);
     }
@@ -1783,19 +1783,27 @@ mod tests {
     #[test]
     fn test_min_max() {
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).max(0),
+            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]])
+                .unwrap()
+                .max(0),
             vec!(4, 5, 6)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).max(1),
+            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]])
+                .unwrap()
+                .max(1),
             vec!(3, 6)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]]).min(0),
+            DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]])
+                .unwrap()
+                .min(0),
             vec!(1., 2., 3.)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]]).min(1),
+            DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]])
+                .unwrap()
+                .min(1),
             vec!(1., 4.)
         );
     }
@@ -1803,11 +1811,15 @@ mod tests {
     #[test]
     fn test_argmax() {
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 5, 3], &[4, 2, 6]]).argmax(0),
+            DenseMatrix::from_2d_array(&[&[1, 5, 3], &[4, 2, 6]])
+                .unwrap()
+                .argmax(0),
             vec!(1, 0, 1)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[4, 2, 3], &[1, 5, 6]]).argmax(1),
+            DenseMatrix::from_2d_array(&[&[4, 2, 3], &[1, 5, 6]])
+                .unwrap()
+                .argmax(1),
             vec!(0, 2)
         );
     }
@@ -1815,168 +1827,181 @@ mod tests {
     #[test]
     fn test_sum() {
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).sum(0),
+            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]])
+                .unwrap()
+                .sum(0),
             vec!(5, 7, 9)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]]).sum(1),
+            DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]])
+                .unwrap()
+                .sum(1),
             vec!(6., 15.)
         );
     }
 
     #[test]
     fn test_abs() {
-        let mut x = DenseMatrix::from_2d_array(&[&[-1, 2, -3], &[4, -5, 6]]);
+        let mut x = DenseMatrix::from_2d_array(&[&[-1, 2, -3], &[4, -5, 6]]).unwrap();
         x.abs_mut();
-        assert_eq!(x, DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]));
+        assert_eq!(
+            x,
+            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap()
+        );
     }
 
     #[test]
     fn test_neg() {
-        let mut x = DenseMatrix::from_2d_array(&[&[-1, 2, -3], &[4, -5, 6]]);
+        let mut x = DenseMatrix::from_2d_array(&[&[-1, 2, -3], &[4, -5, 6]]).unwrap();
         x.neg_mut();
-        assert_eq!(x, DenseMatrix::from_2d_array(&[&[1, -2, 3], &[-4, 5, -6]]));
+        assert_eq!(
+            x,
+            DenseMatrix::from_2d_array(&[&[1, -2, 3], &[-4, 5, -6]]).unwrap()
+        );
     }
 
     #[test]
     fn test_copy_from() {
-        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         let mut y = DenseMatrix::<i32>::zeros(2, 3);
         y.copy_from(&x);
-        assert_eq!(y, DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]));
+        assert_eq!(
+            y,
+            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap()
+        );
     }
 
     #[test]
     fn test_init() {
-        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         assert_eq!(
             DenseMatrix::<i32>::zeros(2, 2),
-            DenseMatrix::from_2d_array(&[&[0, 0], &[0, 0]])
+            DenseMatrix::from_2d_array(&[&[0, 0], &[0, 0]]).unwrap()
         );
         assert_eq!(
             DenseMatrix::<i32>::ones(2, 2),
-            DenseMatrix::from_2d_array(&[&[1, 1], &[1, 1]])
+            DenseMatrix::from_2d_array(&[&[1, 1], &[1, 1]]).unwrap()
         );
         assert_eq!(
             DenseMatrix::<i32>::eye(3),
-            DenseMatrix::from_2d_array(&[&[1, 0, 0], &[0, 1, 0], &[0, 0, 1]])
+            DenseMatrix::from_2d_array(&[&[1, 0, 0], &[0, 1, 0], &[0, 0, 1]]).unwrap()
         );
         assert_eq!(
-            DenseMatrix::from_slice(x.slice(0..2, 0..2).as_ref()),
+            DenseMatrix::from_slice(x.slice(0..2, 0..2).as_ref()), // internal only?
-            DenseMatrix::from_2d_array(&[&[1, 2], &[4, 5]])
+            DenseMatrix::from_2d_array(&[&[1, 2], &[4, 5]]).unwrap()
         );
         assert_eq!(
-            DenseMatrix::from_row(x.get_row(0).as_ref()),
+            DenseMatrix::from_row(x.get_row(0).as_ref()), // internal only?
-            DenseMatrix::from_2d_array(&[&[1, 2, 3]])
+            DenseMatrix::from_2d_array(&[&[1, 2, 3]]).unwrap()
         );
         assert_eq!(
-            DenseMatrix::from_column(x.get_col(0).as_ref()),
+            DenseMatrix::from_column(x.get_col(0).as_ref()), // internal only?
-            DenseMatrix::from_2d_array(&[&[1], &[4]])
+            DenseMatrix::from_2d_array(&[&[1], &[4]]).unwrap()
         );
     }
 
     #[test]
     fn test_transpose() {
-        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         assert_eq!(
             x.transpose(),
-            DenseMatrix::from_2d_array(&[&[1, 4], &[2, 5], &[3, 6]])
+            DenseMatrix::from_2d_array(&[&[1, 4], &[2, 5], &[3, 6]]).unwrap()
         );
     }
 
     #[test]
     fn test_reshape() {
-        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         assert_eq!(
             x.reshape(3, 2, 0),
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]])
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]).unwrap()
         );
         assert_eq!(
             x.reshape(3, 2, 1),
-            DenseMatrix::from_2d_array(&[&[1, 4], &[2, 5], &[3, 6]])
+            DenseMatrix::from_2d_array(&[&[1, 4], &[2, 5], &[3, 6]]).unwrap()
         );
     }
 
     #[test]
     #[should_panic]
     fn test_failed_reshape() {
-        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         assert_eq!(
             x.reshape(4, 2, 0),
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]])
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]).unwrap()
         );
     }
 
     #[test]
     fn test_matmul() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]);
+        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]).unwrap();
         assert_eq!(
             a.matmul(&(*b.slice(0..3, 0..2))),
-            DenseMatrix::from_2d_array(&[&[22, 28], &[49, 64]])
+            DenseMatrix::from_2d_array(&[&[22, 28], &[49, 64]]).unwrap()
         );
         assert_eq!(
             a.matmul(&b),
-            DenseMatrix::from_2d_array(&[&[22, 28], &[49, 64]])
+            DenseMatrix::from_2d_array(&[&[22, 28], &[49, 64]]).unwrap()
         );
     }
 
     #[test]
     fn test_concat() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[5, 6], &[7, 8]]);
+        let b = DenseMatrix::from_2d_array(&[&[5, 6], &[7, 8]]).unwrap();
 
         assert_eq!(
             DenseMatrix::concatenate_1d(&[&vec!(1, 2, 3), &vec!(4, 5, 6)], 0),
-            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]])
+            DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap()
         );
         assert_eq!(
             DenseMatrix::concatenate_1d(&[&vec!(1, 2), &vec!(3, 4)], 1),
-            DenseMatrix::from_2d_array(&[&[1, 3], &[2, 4]])
+            DenseMatrix::from_2d_array(&[&[1, 3], &[2, 4]]).unwrap()
         );
         assert_eq!(
             DenseMatrix::concatenate_2d(&[&a, &b], 0),
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6], &[7, 8]])
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6], &[7, 8]]).unwrap()
         );
         assert_eq!(
             DenseMatrix::concatenate_2d(&[&a, &b], 1),
-            DenseMatrix::from_2d_array(&[&[1, 2, 5, 6], &[3, 4, 7, 8]])
+            DenseMatrix::from_2d_array(&[&[1, 2, 5, 6], &[3, 4, 7, 8]]).unwrap()
         );
     }
 
     #[test]
     fn test_take() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]);
+        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]).unwrap();
 
         assert_eq!(
             a.take(&[0, 2], 1),
-            DenseMatrix::from_2d_array(&[&[1, 3], &[4, 6]])
+            DenseMatrix::from_2d_array(&[&[1, 3], &[4, 6]]).unwrap()
         );
         assert_eq!(
             b.take(&[0, 2], 0),
-            DenseMatrix::from_2d_array(&[&[1, 2], &[5, 6]])
+            DenseMatrix::from_2d_array(&[&[1, 2], &[5, 6]]).unwrap()
         );
     }
 
     #[test]
     fn test_merge() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]).unwrap();
 
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6], &[7, 8]]),
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6], &[7, 8]]).unwrap(),
             a.merge_1d(&[&vec!(5, 6), &vec!(7, 8)], 0, true)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[5, 6], &[7, 8], &[1, 2], &[3, 4]]),
+            DenseMatrix::from_2d_array(&[&[5, 6], &[7, 8], &[1, 2], &[3, 4]]).unwrap(),
             a.merge_1d(&[&vec!(5, 6), &vec!(7, 8)], 0, false)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2, 5, 7], &[3, 4, 6, 8]]),
+            DenseMatrix::from_2d_array(&[&[1, 2, 5, 7], &[3, 4, 6, 8]]).unwrap(),
             a.merge_1d(&[&vec!(5, 6), &vec!(7, 8)], 1, true)
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[5, 7, 1, 2], &[6, 8, 3, 4]]),
+            DenseMatrix::from_2d_array(&[&[5, 7, 1, 2], &[6, 8, 3, 4]]).unwrap(),
             a.merge_1d(&[&vec!(5, 6), &vec!(7, 8)], 1, false)
         );
     }
@@ -1984,20 +2009,28 @@ mod tests {
     #[test]
     fn test_ops() {
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]).mul_scalar(2),
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]])
-            DenseMatrix::from_2d_array(&[&[2, 4], &[6, 8]])
+                .unwrap()
+                .mul_scalar(2),
+            DenseMatrix::from_2d_array(&[&[2, 4], &[6, 8]]).unwrap()
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]).add_scalar(2),
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]])
-            DenseMatrix::from_2d_array(&[&[3, 4], &[5, 6]])
+                .unwrap()
+                .add_scalar(2),
+            DenseMatrix::from_2d_array(&[&[3, 4], &[5, 6]]).unwrap()
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]).sub_scalar(1),
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]])
-            DenseMatrix::from_2d_array(&[&[0, 1], &[2, 3]])
+                .unwrap()
+                .sub_scalar(1),
+            DenseMatrix::from_2d_array(&[&[0, 1], &[2, 3]]).unwrap()
         );
         assert_eq!(
-            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]).div_scalar(2),
+            DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]])
-            DenseMatrix::from_2d_array(&[&[0, 1], &[1, 2]])
+                .unwrap()
+                .div_scalar(2),
+            DenseMatrix::from_2d_array(&[&[0, 1], &[1, 2]]).unwrap()
         );
     }
 
@@ -2011,42 +2044,45 @@ mod tests {
 
     #[test]
     fn test_vstack() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let b = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         let expected = DenseMatrix::from_2d_array(&[
             &[1, 2, 3],
             &[4, 5, 6],
             &[7, 8, 9],
             &[1, 2, 3],
             &[4, 5, 6],
-        ]);
+        ])
+        .unwrap();
         let result = a.v_stack(&b);
         assert_eq!(result, expected);
     }
 
     #[test]
     fn test_hstack() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]);
+        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]).unwrap();
         let expected =
-            DenseMatrix::from_2d_array(&[&[1, 2, 3, 1, 2], &[4, 5, 6, 3, 4], &[7, 8, 9, 5, 6]]);
+            DenseMatrix::from_2d_array(&[&[1, 2, 3, 1, 2], &[4, 5, 6, 3, 4], &[7, 8, 9, 5, 6]])
+                .unwrap();
         let result = a.h_stack(&b);
         assert_eq!(result, expected);
     }
 
     #[test]
     fn test_map() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
-        let expected = DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0], &[4.0, 5.0, 6.0]]);
+        let expected = DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0], &[4.0, 5.0, 6.0]]).unwrap();
         let result: DenseMatrix<f64> = a.map(|&v| v as f64);
         assert_eq!(result, expected);
     }
 
     #[test]
     fn scale() {
-        let mut m = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]]);
+        let mut m = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]]).unwrap();
-        let expected_0 = DenseMatrix::from_2d_array(&[&[-1., -1., -1.], &[1., 1., 1.]]);
+        let expected_0 = DenseMatrix::from_2d_array(&[&[-1., -1., -1.], &[1., 1., 1.]]).unwrap();
-        let expected_1 = DenseMatrix::from_2d_array(&[&[-1.22, 0.0, 1.22], &[-1.22, 0.0, 1.22]]);
+        let expected_1 =
+            DenseMatrix::from_2d_array(&[&[-1.22, 0.0, 1.22], &[-1.22, 0.0, 1.22]]).unwrap();
 
         {
             let mut m = m.clone();
@@ -2060,52 +2096,52 @@ mod tests {
 
     #[test]
     fn test_pow_mut() {
-        let mut a = DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0], &[4.0, 5.0, 6.0]]);
+        let mut a = DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0], &[4.0, 5.0, 6.0]]).unwrap();
         a.pow_mut(2.0);
         assert_eq!(
             a,
-            DenseMatrix::from_2d_array(&[&[1.0, 4.0, 9.0], &[16.0, 25.0, 36.0]])
+            DenseMatrix::from_2d_array(&[&[1.0, 4.0, 9.0], &[16.0, 25.0, 36.0]]).unwrap()
         );
     }
 
     #[test]
     fn test_ab() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[5, 6], &[7, 8]]);
+        let b = DenseMatrix::from_2d_array(&[&[5, 6], &[7, 8]]).unwrap();
         assert_eq!(
             a.ab(false, &b, false),
-            DenseMatrix::from_2d_array(&[&[19, 22], &[43, 50]])
+            DenseMatrix::from_2d_array(&[&[19, 22], &[43, 50]]).unwrap()
         );
         assert_eq!(
             a.ab(true, &b, false),
-            DenseMatrix::from_2d_array(&[&[26, 30], &[38, 44]])
+            DenseMatrix::from_2d_array(&[&[26, 30], &[38, 44]]).unwrap()
         );
         assert_eq!(
             a.ab(false, &b, true),
-            DenseMatrix::from_2d_array(&[&[17, 23], &[39, 53]])
+            DenseMatrix::from_2d_array(&[&[17, 23], &[39, 53]]).unwrap()
         );
         assert_eq!(
             a.ab(true, &b, true),
-            DenseMatrix::from_2d_array(&[&[23, 31], &[34, 46]])
+            DenseMatrix::from_2d_array(&[&[23, 31], &[34, 46]]).unwrap()
         );
     }
 
     #[test]
     fn test_ax() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
         assert_eq!(
             a.ax(false, &vec![7, 8, 9]).transpose(),
-            DenseMatrix::from_2d_array(&[&[50, 122]])
+            DenseMatrix::from_2d_array(&[&[50, 122]]).unwrap()
         );
         assert_eq!(
             a.ax(true, &vec![7, 8]).transpose(),
-            DenseMatrix::from_2d_array(&[&[39, 54, 69]])
+            DenseMatrix::from_2d_array(&[&[39, 54, 69]]).unwrap()
         );
     }
 
     #[test]
     fn diag() {
-        let x = DenseMatrix::from_2d_array(&[&[0, 1, 2], &[3, 4, 5], &[6, 7, 8]]);
+        let x = DenseMatrix::from_2d_array(&[&[0, 1, 2], &[3, 4, 5], &[6, 7, 8]]).unwrap();
         assert_eq!(x.diag(), vec![0, 4, 8]);
     }
 
@@ -2117,13 +2153,15 @@ mod tests {
             &[68, 590, 37],
             &[69, 660, 46],
             &[73, 600, 55],
-        ]);
+        ])
+        .unwrap();
         let mut result = DenseMatrix::zeros(3, 3);
         let expected = DenseMatrix::from_2d_array(&[
             &[11.5, 50.0, 34.75],
             &[50.0, 1250.0, 205.0],
             &[34.75, 205.0, 110.0],
-        ]);
+        ])
+        .unwrap();
 
         a.cov(&mut result);
 

src/linalg/basic/matrix.rs

@@ -19,6 +19,8 @@ use crate::linalg::traits::svd::SVDDecomposable;
 use crate::numbers::basenum::Number;
 use crate::numbers::realnum::RealNumber;
 
+use crate::error::Failed;
+
 /// Dense matrix
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone)]
@@ -50,26 +52,26 @@ pub struct DenseMatrixMutView<'a, T: Debug + Display + Copy + Sized> {
 }
 
 impl<'a, T: Debug + Display + Copy + Sized> DenseMatrixView<'a, T> {
-    fn new(m: &'a DenseMatrix<T>, rows: Range<usize>, cols: Range<usize>) -> Self {
+    fn new(
-        let (start, end, stride) = if m.column_major {
+        m: &'a DenseMatrix<T>,
-            (
+        vrows: Range<usize>,
-                rows.start + cols.start * m.nrows,
+        vcols: Range<usize>,
-                rows.end + (cols.end - 1) * m.nrows,
+    ) -> Result<Self, Failed> {
-                m.nrows,
+        if m.is_valid_view(m.shape().0, m.shape().1, &vrows, &vcols) {
-            )
+            Err(Failed::input(
+                "The specified view is outside of the matrix range",
+            ))
         } else {
-            (
+            let (start, end, stride) =
-                rows.start * m.ncols + cols.start,
+                m.stride_range(m.shape().0, m.shape().1, &vrows, &vcols, m.column_major);
-                (rows.end - 1) * m.ncols + cols.end,
+
-                m.ncols,
+            Ok(DenseMatrixView {
-            )
+                values: &m.values[start..end],
-        };
+                stride,
-        DenseMatrixView {
+                nrows: vrows.end - vrows.start,
-            values: &m.values[start..end],
+                ncols: vcols.end - vcols.start,
-            stride,
+                column_major: m.column_major,
-            nrows: rows.end - rows.start,
+            })
-            ncols: cols.end - cols.start,
-            column_major: m.column_major,
         }
     }
 
@@ -102,26 +104,26 @@ impl<'a, T: Debug + Display + Copy + Sized> fmt::Display for DenseMatrixView<'a,
 }
 
 impl<'a, T: Debug + Display + Copy + Sized> DenseMatrixMutView<'a, T> {
-    fn new(m: &'a mut DenseMatrix<T>, rows: Range<usize>, cols: Range<usize>) -> Self {
+    fn new(
-        let (start, end, stride) = if m.column_major {
+        m: &'a mut DenseMatrix<T>,
-            (
+        vrows: Range<usize>,
-                rows.start + cols.start * m.nrows,
+        vcols: Range<usize>,
-                rows.end + (cols.end - 1) * m.nrows,
+    ) -> Result<Self, Failed> {
-                m.nrows,
+        if m.is_valid_view(m.shape().0, m.shape().1, &vrows, &vcols) {
-            )
+            Err(Failed::input(
+                "The specified view is outside of the matrix range",
+            ))
         } else {
-            (
+            let (start, end, stride) =
-                rows.start * m.ncols + cols.start,
+                m.stride_range(m.shape().0, m.shape().1, &vrows, &vcols, m.column_major);
-                (rows.end - 1) * m.ncols + cols.end,
+
-                m.ncols,
+            Ok(DenseMatrixMutView {
-            )
+                values: &mut m.values[start..end],
-        };
+                stride,
-        DenseMatrixMutView {
+                nrows: vrows.end - vrows.start,
-            values: &mut m.values[start..end],
+                ncols: vcols.end - vcols.start,
-            stride,
+                column_major: m.column_major,
-            nrows: rows.end - rows.start,
+            })
-            ncols: cols.end - cols.start,
-            column_major: m.column_major,
         }
     }
 
@@ -182,42 +184,102 @@ impl<'a, T: Debug + Display + Copy + Sized> fmt::Display for DenseMatrixMutView<
 impl<T: Debug + Display + Copy + Sized> DenseMatrix<T> {
     /// Create new instance of `DenseMatrix` without copying data.
     /// `values` should be in column-major order.
-    pub fn new(nrows: usize, ncols: usize, values: Vec<T>, column_major: bool) -> Self {
+    pub fn new(
-        DenseMatrix {
+        nrows: usize,
-            ncols,
+        ncols: usize,
-            nrows,
+        values: Vec<T>,
-            values,
+        column_major: bool,
-            column_major,
+    ) -> Result<Self, Failed> {
+        let data_len = values.len();
+        if nrows * ncols != values.len() {
+            Err(Failed::input(&format!(
+                "The specified shape: (cols: {ncols}, rows: {nrows}) does not align with data len: {data_len}"
+            )))
+        } else {
+            Ok(DenseMatrix {
+                ncols,
+                nrows,
+                values,
+                column_major,
+            })
         }
     }
 
     /// New instance of `DenseMatrix` from 2d array.
-    pub fn from_2d_array(values: &[&[T]]) -> Self {
+    pub fn from_2d_array(values: &[&[T]]) -> Result<Self, Failed> {
-        DenseMatrix::from_2d_vec(&values.iter().map(|row| Vec::from(*row)).collect::<Vec<_>>())
+        DenseMatrix::from_2d_vec(&values.iter().map(|row| Vec::from(*row)).collect())
     }
 
     /// New instance of `DenseMatrix` from 2d vector.
-    pub fn from_2d_vec(values: &[Vec<T>]) -> Self {
+    #[allow(clippy::ptr_arg)]
-        let nrows = values.len();
+    pub fn from_2d_vec(values: &Vec<Vec<T>>) -> Result<Self, Failed> {
-        let ncols = values
+        if values.is_empty() || values[0].is_empty() {
-            .first()
+            Err(Failed::input(
-            .unwrap_or_else(|| panic!("Cannot create 2d matrix from an empty vector"))
+                "The 2d vec provided is empty; cannot instantiate the matrix",
-            .len();
+            ))
-        let mut m_values = Vec::with_capacity(nrows * ncols);
+        } else {
+            let nrows = values.len();
+            let ncols = values
+                .first()
+                .unwrap_or_else(|| {
+                    panic!("Invalid state: Cannot create 2d matrix from an empty vector")
+                })
+                .len();
+            let mut m_values = Vec::with_capacity(nrows * ncols);
 
-        for c in 0..ncols {
+            for c in 0..ncols {
-            for r in values.iter().take(nrows) {
+                for r in values.iter().take(nrows) {
-                m_values.push(r[c])
+                    m_values.push(r[c])
+                }
             }
-        }
 
-        DenseMatrix::new(nrows, ncols, m_values, true)
+            DenseMatrix::new(nrows, ncols, m_values, true)
+        }
     }
 
     /// Iterate over values of matrix
     pub fn iter(&self) -> Iter<'_, T> {
         self.values.iter()
     }
+
+    ///  Check if the size of the requested view is bounded to matrix rows/cols count
+    fn is_valid_view(
+        &self,
+        n_rows: usize,
+        n_cols: usize,
+        vrows: &Range<usize>,
+        vcols: &Range<usize>,
+    ) -> bool {
+        !(vrows.end <= n_rows
+            && vcols.end <= n_cols
+            && vrows.start <= n_rows
+            && vcols.start <= n_cols)
+    }
+
+    ///  Compute the range of the requested view: start, end, size of the slice
+    fn stride_range(
+        &self,
+        n_rows: usize,
+        n_cols: usize,
+        vrows: &Range<usize>,
+        vcols: &Range<usize>,
+        column_major: bool,
+    ) -> (usize, usize, usize) {
+        let (start, end, stride) = if column_major {
+            (
+                vrows.start + vcols.start * n_rows,
+                vrows.end + (vcols.end - 1) * n_rows,
+                n_rows,
+            )
+        } else {
+            (
+                vrows.start * n_cols + vcols.start,
+                (vrows.end - 1) * n_cols + vcols.end,
+                n_cols,
+            )
+        };
+        (start, end, stride)
+    }
 }
 
 impl<T: Debug + Display + Copy + Sized> fmt::Display for DenseMatrix<T> {
@@ -304,6 +366,7 @@ where
 impl<T: Debug + Display + Copy + Sized> Array<T, (usize, usize)> for DenseMatrix<T> {
     fn get(&self, pos: (usize, usize)) -> &T {
         let (row, col) = pos;
+
         if row >= self.nrows || col >= self.ncols {
             panic!(
                 "Invalid index ({},{}) for {}x{} matrix",
@@ -383,15 +446,15 @@ impl<T: Debug + Display + Copy + Sized> MutArrayView2<T> for DenseMatrix<T> {}
 
 impl<T: Debug + Display + Copy + Sized> Array2<T> for DenseMatrix<T> {
     fn get_row<'a>(&'a self, row: usize) -> Box<dyn ArrayView1<T> + 'a> {
-        Box::new(DenseMatrixView::new(self, row..row + 1, 0..self.ncols))
+        Box::new(DenseMatrixView::new(self, row..row + 1, 0..self.ncols).unwrap())
     }
 
     fn get_col<'a>(&'a self, col: usize) -> Box<dyn ArrayView1<T> + 'a> {
-        Box::new(DenseMatrixView::new(self, 0..self.nrows, col..col + 1))
+        Box::new(DenseMatrixView::new(self, 0..self.nrows, col..col + 1).unwrap())
     }
 
     fn slice<'a>(&'a self, rows: Range<usize>, cols: Range<usize>) -> Box<dyn ArrayView2<T> + 'a> {
-        Box::new(DenseMatrixView::new(self, rows, cols))
+        Box::new(DenseMatrixView::new(self, rows, cols).unwrap())
     }
 
     fn slice_mut<'a>(
@@ -402,15 +465,17 @@ impl<T: Debug + Display + Copy + Sized> Array2<T> for DenseMatrix<T> {
     where
         Self: Sized,
     {
-        Box::new(DenseMatrixMutView::new(self, rows, cols))
+        Box::new(DenseMatrixMutView::new(self, rows, cols).unwrap())
     }
 
+    // private function so for now assume infalible
     fn fill(nrows: usize, ncols: usize, value: T) -> Self {
-        DenseMatrix::new(nrows, ncols, vec![value; nrows * ncols], true)
+        DenseMatrix::new(nrows, ncols, vec![value; nrows * ncols], true).unwrap()
     }
 
+    // private function so for now assume infalible
     fn from_iterator<I: Iterator<Item = T>>(iter: I, nrows: usize, ncols: usize, axis: u8) -> Self {
-        DenseMatrix::new(nrows, ncols, iter.collect(), axis != 0)
+        DenseMatrix::new(nrows, ncols, iter.collect(), axis != 0).unwrap()
     }
 
     fn transpose(&self) -> Self {
@@ -544,15 +609,74 @@ mod tests {
     use approx::relative_eq;
 
     #[test]
-    fn test_display() {
+    fn test_instantiate_from_2d() {
         let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]);
+        assert!(x.is_ok());
+    }
+    #[test]
+    fn test_instantiate_from_2d_empty() {
+        let input: &[&[f64]] = &[&[]];
+        let x = DenseMatrix::from_2d_array(input);
+        assert!(x.is_err());
+    }
+    #[test]
+    fn test_instantiate_from_2d_empty2() {
+        let input: &[&[f64]] = &[&[], &[]];
+        let x = DenseMatrix::from_2d_array(input);
+        assert!(x.is_err());
+    }
+    #[test]
+    fn test_instantiate_ok_view1() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
+        let v = DenseMatrixView::new(&x, 0..2, 0..2);
+        assert!(v.is_ok());
+    }
+    #[test]
+    fn test_instantiate_ok_view2() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
+        let v = DenseMatrixView::new(&x, 0..3, 0..3);
+        assert!(v.is_ok());
+    }
+    #[test]
+    fn test_instantiate_ok_view3() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
+        let v = DenseMatrixView::new(&x, 2..3, 0..3);
+        assert!(v.is_ok());
+    }
+    #[test]
+    fn test_instantiate_ok_view4() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
+        let v = DenseMatrixView::new(&x, 3..3, 0..3);
+        assert!(v.is_ok());
+    }
+    #[test]
+    fn test_instantiate_err_view1() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
+        let v = DenseMatrixView::new(&x, 3..4, 0..3);
+        assert!(v.is_err());
+    }
+    #[test]
+    fn test_instantiate_err_view2() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
+        let v = DenseMatrixView::new(&x, 0..3, 3..4);
+        assert!(v.is_err());
+    }
+    #[test]
+    fn test_instantiate_err_view3() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
+        let v = DenseMatrixView::new(&x, 0..3, 4..3);
+        assert!(v.is_err());
+    }
+    #[test]
+    fn test_display() {
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
 
         println!("{}", &x);
     }
 
     #[test]
     fn test_get_row_col() {
-        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]);
+        let x = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
 
         assert_eq!(15.0, x.get_col(1).sum());
         assert_eq!(15.0, x.get_row(1).sum());
@@ -561,7 +685,7 @@ mod tests {
 
     #[test]
     fn test_row_major() {
-        let mut x = DenseMatrix::new(2, 3, vec![1, 2, 3, 4, 5, 6], false);
+        let mut x = DenseMatrix::new(2, 3, vec![1, 2, 3, 4, 5, 6], false).unwrap();
 
         assert_eq!(5, *x.get_col(1).get(1));
         assert_eq!(7, x.get_col(1).sum());
@@ -575,7 +699,8 @@ mod tests {
 
     #[test]
     fn test_get_slice() {
-        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9], &[10, 11, 12]]);
+        let x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9], &[10, 11, 12]])
+            .unwrap();
 
         assert_eq!(
             vec![4, 5, 6],
@@ -589,7 +714,7 @@ mod tests {
 
     #[test]
     fn test_iter_mut() {
-        let mut x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]);
+        let mut x = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]).unwrap();
 
         assert_eq!(vec![1, 4, 7, 2, 5, 8, 3, 6, 9], x.values);
         // add +2 to some elements
@@ -625,7 +750,8 @@ mod tests {
     #[test]
     fn test_str_array() {
         let mut x =
-            DenseMatrix::from_2d_array(&[&["1", "2", "3"], &["4", "5", "6"], &["7", "8", "9"]]);
+            DenseMatrix::from_2d_array(&[&["1", "2", "3"], &["4", "5", "6"], &["7", "8", "9"]])
+                .unwrap();
 
         assert_eq!(vec!["1", "4", "7", "2", "5", "8", "3", "6", "9"], x.values);
         x.iterator_mut(0).for_each(|v| *v = "str");
@@ -637,7 +763,7 @@ mod tests {
 
     #[test]
     fn test_transpose() {
-        let x = DenseMatrix::<&str>::from_2d_array(&[&["1", "2", "3"], &["4", "5", "6"]]);
+        let x = DenseMatrix::<&str>::from_2d_array(&[&["1", "2", "3"], &["4", "5", "6"]]).unwrap();
 
         assert_eq!(vec!["1", "4", "2", "5", "3", "6"], x.values);
         assert!(x.column_major);
@@ -664,8 +790,8 @@ mod tests {
 
     #[test]
     fn test_take() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]);
+        let b = DenseMatrix::from_2d_array(&[&[1, 2], &[3, 4], &[5, 6]]).unwrap();
 
         println!("{a}");
         // take column 0 and 2
@@ -677,7 +803,7 @@ mod tests {
 
     #[test]
     fn test_mut() {
-        let a = DenseMatrix::from_2d_array(&[&[1.3, -2.1, 3.4], &[-4., -5.3, 6.1]]);
+        let a = DenseMatrix::from_2d_array(&[&[1.3, -2.1, 3.4], &[-4., -5.3, 6.1]]).unwrap();
 
         let a = a.abs();
         assert_eq!(vec![1.3, 4.0, 2.1, 5.3, 3.4, 6.1], a.values);
@@ -688,7 +814,8 @@ mod tests {
 
     #[test]
     fn test_reshape() {
-        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9], &[10, 11, 12]]);
+        let a = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9], &[10, 11, 12]])
+            .unwrap();
 
         let a = a.reshape(2, 6, 0);
         assert_eq!(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12], a.values);
@@ -701,13 +828,15 @@ mod tests {
 
     #[test]
     fn test_eq() {
-        let a = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]]);
+        let a = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.]]).unwrap();
-        let b = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]);
+        let b = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[4., 5., 6.], &[7., 8., 9.]]).unwrap();
         let c = DenseMatrix::from_2d_array(&[
             &[1. + f32::EPSILON, 2., 3.],
             &[4., 5., 6. + f32::EPSILON],
-        ]);
+        ])
-        let d = DenseMatrix::from_2d_array(&[&[1. + 0.5, 2., 3.], &[4., 5., 6. + f32::EPSILON]]);
+        .unwrap();
+        let d = DenseMatrix::from_2d_array(&[&[1. + 0.5, 2., 3.], &[4., 5., 6. + f32::EPSILON]])
+            .unwrap();
 
         assert!(!relative_eq!(a, b));
         assert!(!relative_eq!(a, d));

src/linalg/basic/vector.rs

@@ -55,6 +55,7 @@ impl<T: Debug + Display + Copy + Sized> Array<T, usize> for Vec<T> {
 
 impl<T: Debug + Display + Copy + Sized> MutArray<T, usize> for Vec<T> {
     fn set(&mut self, i: usize, x: T) {
+        // NOTE: this panics in case of out of bounds index
         self[i] = x
     }
 

src/linalg/traits/cholesky.rs

@@ -15,7 +15,7 @@
 //!                 &[25., 15., -5.],
 //!                 &[15., 18., 0.],
 //!                 &[-5., 0., 11.]
-//!         ]);
+//!         ]).unwrap();
 //!
 //! let cholesky = A.cholesky().unwrap();
 //! let lower_triangular: DenseMatrix<f64> = cholesky.L();
@@ -175,11 +175,14 @@ mod tests {
     )]
     #[test]
     fn cholesky_decompose() {
-        let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0., 11.]]);
+        let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0., 11.]])
+            .unwrap();
         let l =
-            DenseMatrix::from_2d_array(&[&[5.0, 0.0, 0.0], &[3.0, 3.0, 0.0], &[-1.0, 1.0, 3.0]]);
+            DenseMatrix::from_2d_array(&[&[5.0, 0.0, 0.0], &[3.0, 3.0, 0.0], &[-1.0, 1.0, 3.0]])
+                .unwrap();
         let u =
-            DenseMatrix::from_2d_array(&[&[5.0, 3.0, -1.0], &[0.0, 3.0, 1.0], &[0.0, 0.0, 3.0]]);
+            DenseMatrix::from_2d_array(&[&[5.0, 3.0, -1.0], &[0.0, 3.0, 1.0], &[0.0, 0.0, 3.0]])
+                .unwrap();
         let cholesky = a.cholesky().unwrap();
 
         assert!(relative_eq!(cholesky.L().abs(), l.abs(), epsilon = 1e-4));
@@ -197,9 +200,10 @@ mod tests {
     )]
     #[test]
     fn cholesky_solve_mut() {
-        let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0., 11.]]);
+        let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0., 11.]])
-        let b = DenseMatrix::from_2d_array(&[&[40., 51., 28.]]);
+            .unwrap();
-        let expected = DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0]]);
+        let b = DenseMatrix::from_2d_array(&[&[40., 51., 28.]]).unwrap();
+        let expected = DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0]]).unwrap();
 
         let cholesky = a.cholesky().unwrap();
 

src/linalg/traits/evd.rs

@@ -19,7 +19,7 @@
 //!                  &[0.9000, 0.4000, 0.7000],
 //!                  &[0.4000, 0.5000, 0.3000],
 //!                  &[0.7000, 0.3000, 0.8000],
-//!         ]);
+//!         ]).unwrap();
 //!
 //! let evd = A.evd(true).unwrap();
 //! let eigenvectors: DenseMatrix<f64> = evd.V;
@@ -820,7 +820,8 @@ mod tests {
             &[0.9000, 0.4000, 0.7000],
             &[0.4000, 0.5000, 0.3000],
             &[0.7000, 0.3000, 0.8000],
-        ]);
+        ])
+        .unwrap();
 
         let eigen_values: Vec<f64> = vec![1.7498382, 0.3165784, 0.1335834];
 
@@ -828,7 +829,8 @@ mod tests {
             &[0.6881997, -0.07121225, 0.7220180],
             &[0.3700456, 0.89044952, -0.2648886],
             &[0.6240573, -0.44947578, -0.6391588],
-        ]);
+        ])
+        .unwrap();
 
         let evd = A.evd(true).unwrap();
 
@@ -852,7 +854,8 @@ mod tests {
             &[0.9000, 0.4000, 0.7000],
             &[0.4000, 0.5000, 0.3000],
             &[0.8000, 0.3000, 0.8000],
-        ]);
+        ])
+        .unwrap();
 
         let eigen_values: Vec<f64> = vec![1.79171122, 0.31908143, 0.08920735];
 
@@ -860,7 +863,8 @@ mod tests {
             &[0.7178958, 0.05322098, 0.6812010],
             &[0.3837711, -0.84702111, -0.1494582],
             &[0.6952105, 0.43984484, -0.7036135],
-        ]);
+        ])
+        .unwrap();
 
         let evd = A.evd(false).unwrap();
 
@@ -885,7 +889,8 @@ mod tests {
             &[4.0, -1.0, 1.0, 1.0],
             &[1.0, 1.0, 3.0, -2.0],
             &[1.0, 1.0, 4.0, -1.0],
-        ]);
+        ])
+        .unwrap();
 
         let eigen_values_d: Vec<f64> = vec![0.0, 2.0, 2.0, 0.0];
         let eigen_values_e: Vec<f64> = vec![2.2361, 0.9999, -0.9999, -2.2361];
@@ -895,7 +900,8 @@ mod tests {
             &[-0.6707, 0.1059, 0.901, 0.6289],
             &[0.9159, -0.1378, 0.3816, 0.0806],
             &[0.6707, 0.1059, 0.901, -0.6289],
-        ]);
+        ])
+        .unwrap();
 
         let evd = A.evd(false).unwrap();
 

src/linalg/traits/high_order.rs

@@ -12,9 +12,9 @@ pub trait HighOrderOperations<T: Number>: Array2<T> {
     /// use smartcore::linalg::traits::high_order::HighOrderOperations;
     /// use smartcore::linalg::basic::arrays::Array2;
     ///
-    /// let a = DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.]]);
+    /// let a = DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.]]).unwrap();
-    /// let b = DenseMatrix::from_2d_array(&[&[5., 6.], &[7., 8.], &[9., 10.]]);
+    /// let b = DenseMatrix::from_2d_array(&[&[5., 6.], &[7., 8.], &[9., 10.]]).unwrap();
-    /// let expected = DenseMatrix::from_2d_array(&[&[71., 80.], &[92., 104.]]);
+    /// let expected = DenseMatrix::from_2d_array(&[&[71., 80.], &[92., 104.]]).unwrap();
     ///
     /// assert_eq!(a.ab(true, &b, false), expected);
     /// ```

src/linalg/traits/lu.rs

@@ -18,7 +18,7 @@
 //!                  &[1., 2., 3.],
 //!                  &[0., 1., 5.],
 //!                  &[5., 6., 0.]
-//!         ]);
+//!         ]).unwrap();
 //!
 //! let lu = A.lu().unwrap();
 //! let lower: DenseMatrix<f64> = lu.L();
@@ -263,13 +263,13 @@ mod tests {
     )]
     #[test]
     fn decompose() {
-        let a = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[0., 1., 5.], &[5., 6., 0.]]);
+        let a = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[0., 1., 5.], &[5., 6., 0.]]).unwrap();
         let expected_L =
-            DenseMatrix::from_2d_array(&[&[1., 0., 0.], &[0., 1., 0.], &[0.2, 0.8, 1.]]);
+            DenseMatrix::from_2d_array(&[&[1., 0., 0.], &[0., 1., 0.], &[0.2, 0.8, 1.]]).unwrap();
         let expected_U =
-            DenseMatrix::from_2d_array(&[&[5., 6., 0.], &[0., 1., 5.], &[0., 0., -1.]]);
+            DenseMatrix::from_2d_array(&[&[5., 6., 0.], &[0., 1., 5.], &[0., 0., -1.]]).unwrap();
         let expected_pivot =
-            DenseMatrix::from_2d_array(&[&[0., 0., 1.], &[0., 1., 0.], &[1., 0., 0.]]);
+            DenseMatrix::from_2d_array(&[&[0., 0., 1.], &[0., 1., 0.], &[1., 0., 0.]]).unwrap();
         let lu = a.lu().unwrap();
         assert!(relative_eq!(lu.L(), expected_L, epsilon = 1e-4));
         assert!(relative_eq!(lu.U(), expected_U, epsilon = 1e-4));
@@ -281,9 +281,10 @@ mod tests {
     )]
     #[test]
     fn inverse() {
-        let a = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[0., 1., 5.], &[5., 6., 0.]]);
+        let a = DenseMatrix::from_2d_array(&[&[1., 2., 3.], &[0., 1., 5.], &[5., 6., 0.]]).unwrap();
         let expected =
-            DenseMatrix::from_2d_array(&[&[-6.0, 3.6, 1.4], &[5.0, -3.0, -1.0], &[-1.0, 0.8, 0.2]]);
+            DenseMatrix::from_2d_array(&[&[-6.0, 3.6, 1.4], &[5.0, -3.0, -1.0], &[-1.0, 0.8, 0.2]])
+                .unwrap();
         let a_inv = a.lu().and_then(|lu| lu.inverse()).unwrap();
         assert!(relative_eq!(a_inv, expected, epsilon = 1e-4));
     }

src/linalg/traits/qr.rs

@@ -13,7 +13,7 @@
 //!                 &[0.9, 0.4, 0.7],
 //!                 &[0.4, 0.5, 0.3],
 //!                 &[0.7, 0.3, 0.8]
-//!         ]);
+//!         ]).unwrap();
 //!
 //! let qr = A.qr().unwrap();
 //! let orthogonal: DenseMatrix<f64> = qr.Q();
@@ -201,17 +201,20 @@ mod tests {
     )]
     #[test]
     fn decompose() {
-        let a = DenseMatrix::from_2d_array(&[&[0.9, 0.4, 0.7], &[0.4, 0.5, 0.3], &[0.7, 0.3, 0.8]]);
+        let a = DenseMatrix::from_2d_array(&[&[0.9, 0.4, 0.7], &[0.4, 0.5, 0.3], &[0.7, 0.3, 0.8]])
+            .unwrap();
         let q = DenseMatrix::from_2d_array(&[
             &[-0.7448, 0.2436, 0.6212],
             &[-0.331, -0.9432, -0.027],
             &[-0.5793, 0.2257, -0.7832],
-        ]);
+        ])
+        .unwrap();
         let r = DenseMatrix::from_2d_array(&[
             &[-1.2083, -0.6373, -1.0842],
             &[0.0, -0.3064, 0.0682],
             &[0.0, 0.0, -0.1999],
-        ]);
+        ])
+        .unwrap();
         let qr = a.qr().unwrap();
         assert!(relative_eq!(qr.Q().abs(), q.abs(), epsilon = 1e-4));
         assert!(relative_eq!(qr.R().abs(), r.abs(), epsilon = 1e-4));
@@ -223,13 +226,15 @@ mod tests {
     )]
     #[test]
     fn qr_solve_mut() {
-        let a = DenseMatrix::from_2d_array(&[&[0.9, 0.4, 0.7], &[0.4, 0.5, 0.3], &[0.7, 0.3, 0.8]]);
+        let a = DenseMatrix::from_2d_array(&[&[0.9, 0.4, 0.7], &[0.4, 0.5, 0.3], &[0.7, 0.3, 0.8]])
-        let b = DenseMatrix::from_2d_array(&[&[0.5, 0.2], &[0.5, 0.8], &[0.5, 0.3]]);
+            .unwrap();
+        let b = DenseMatrix::from_2d_array(&[&[0.5, 0.2], &[0.5, 0.8], &[0.5, 0.3]]).unwrap();
         let expected_w = DenseMatrix::from_2d_array(&[
             &[-0.2027027, -1.2837838],
             &[0.8783784, 2.2297297],
             &[0.4729730, 0.6621622],
-        ]);
+        ])
+        .unwrap();
         let w = a.qr_solve_mut(b).unwrap();
         assert!(relative_eq!(w, expected_w, epsilon = 1e-2));
     }

src/linalg/traits/stats.rs

@@ -136,8 +136,8 @@ pub trait MatrixPreprocessing<T: RealNumber>: MutArrayView2<T> + Clone {
     /// ```rust
     /// use smartcore::linalg::basic::matrix::DenseMatrix;
     /// use smartcore::linalg::traits::stats::MatrixPreprocessing;
-    /// let mut a = DenseMatrix::from_2d_array(&[&[0., 2., 3.], &[-5., -6., -7.]]);
+    /// let mut a = DenseMatrix::from_2d_array(&[&[0., 2., 3.], &[-5., -6., -7.]]).unwrap();
-    /// let expected = DenseMatrix::from_2d_array(&[&[0., 1., 1.],&[0., 0., 0.]]);
+    /// let expected = DenseMatrix::from_2d_array(&[&[0., 1., 1.],&[0., 0., 0.]]).unwrap();
     /// a.binarize_mut(0.);
     ///
     /// assert_eq!(a, expected);
@@ -159,8 +159,8 @@ pub trait MatrixPreprocessing<T: RealNumber>: MutArrayView2<T> + Clone {
     /// ```rust
     /// use smartcore::linalg::basic::matrix::DenseMatrix;
     /// use smartcore::linalg::traits::stats::MatrixPreprocessing;
-    /// let a = DenseMatrix::from_2d_array(&[&[0., 2., 3.], &[-5., -6., -7.]]);
+    /// let a = DenseMatrix::from_2d_array(&[&[0., 2., 3.], &[-5., -6., -7.]]).unwrap();
-    /// let expected = DenseMatrix::from_2d_array(&[&[0., 1., 1.],&[0., 0., 0.]]);
+    /// let expected = DenseMatrix::from_2d_array(&[&[0., 1., 1.],&[0., 0., 0.]]).unwrap();
     ///
     /// assert_eq!(a.binarize(0.), expected);
     /// ```
@@ -186,7 +186,8 @@ mod tests {
             &[1., 2., 3., 1., 2.],
             &[4., 5., 6., 3., 4.],
             &[7., 8., 9., 5., 6.],
-        ]);
+        ])
+        .unwrap();
         let expected_0 = vec![4., 5., 6., 3., 4.];
         let expected_1 = vec![1.8, 4.4, 7.];
 
@@ -196,7 +197,7 @@ mod tests {
 
     #[test]
     fn test_var() {
-        let m = DenseMatrix::from_2d_array(&[&[1., 2., 3., 4.], &[5., 6., 7., 8.]]);
+        let m = DenseMatrix::from_2d_array(&[&[1., 2., 3., 4.], &[5., 6., 7., 8.]]).unwrap();
         let expected_0 = vec![4., 4., 4., 4.];
         let expected_1 = vec![1.25, 1.25];
 
@@ -211,7 +212,8 @@ mod tests {
         let m = DenseMatrix::from_2d_array(&[
             &[0.0, 0.25, 0.25, 1.25, 1.5, 1.75, 2.75, 3.25],
             &[0.0, 0.25, 0.25, 1.25, 1.5, 1.75, 2.75, 3.25],
-        ]);
+        ])
+        .unwrap();
         let expected_0 = vec![0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0];
         let expected_1 = vec![1.25, 1.25];
 
@@ -230,7 +232,8 @@ mod tests {
             &[1., 2., 3., 1., 2.],
             &[4., 5., 6., 3., 4.],
             &[7., 8., 9., 5., 6.],
-        ]);
+        ])
+        .unwrap();
         let expected_0 = vec![
             2.449489742783178,
             2.449489742783178,
@@ -251,10 +254,10 @@ mod tests {
     #[test]
     fn test_scale() {
         let m: DenseMatrix<f64> =
-            DenseMatrix::from_2d_array(&[&[1., 2., 3., 4.], &[5., 6., 7., 8.]]);
+            DenseMatrix::from_2d_array(&[&[1., 2., 3., 4.], &[5., 6., 7., 8.]]).unwrap();
 
         let expected_0: DenseMatrix<f64> =
-            DenseMatrix::from_2d_array(&[&[-1., -1., -1., -1.], &[1., 1., 1., 1.]]);
+            DenseMatrix::from_2d_array(&[&[-1., -1., -1., -1.], &[1., 1., 1., 1.]]).unwrap();
         let expected_1: DenseMatrix<f64> = DenseMatrix::from_2d_array(&[
             &[
                 -1.3416407864998738,
@@ -268,7 +271,8 @@ mod tests {
                 0.4472135954999579,
                 1.3416407864998738,
             ],
-        ]);
+        ])
+        .unwrap();
 
         assert_eq!(m.mean(0), vec![3.0, 4.0, 5.0, 6.0]);
         assert_eq!(m.mean(1), vec![2.5, 6.5]);

src/linalg/traits/svd.rs

@@ -17,7 +17,7 @@
 //!                 &[0.9, 0.4, 0.7],
 //!                 &[0.4, 0.5, 0.3],
 //!                 &[0.7, 0.3, 0.8]
-//!         ]);
+//!         ]).unwrap();
 //!
 //! let svd = A.svd().unwrap();
 //! let u: DenseMatrix<f64> = svd.U;
@@ -489,7 +489,8 @@ mod tests {
             &[0.9000, 0.4000, 0.7000],
             &[0.4000, 0.5000, 0.3000],
             &[0.7000, 0.3000, 0.8000],
-        ]);
+        ])
+        .unwrap();
 
         let s: Vec<f64> = vec![1.7498382, 0.3165784, 0.1335834];
 
@@ -497,13 +498,15 @@ mod tests {
             &[0.6881997, -0.07121225, 0.7220180],
             &[0.3700456, 0.89044952, -0.2648886],
             &[0.6240573, -0.44947578, -0.639158],
-        ]);
+        ])
+        .unwrap();
 
         let V = DenseMatrix::from_2d_array(&[
             &[0.6881997, -0.07121225, 0.7220180],
             &[0.3700456, 0.89044952, -0.2648886],
             &[0.6240573, -0.44947578, -0.6391588],
-        ]);
+        ])
+        .unwrap();
 
         let svd = A.svd().unwrap();
 
@@ -577,7 +580,8 @@ mod tests {
                 -0.2158704,
                 -0.27529472,
             ],
-        ]);
+        ])
+        .unwrap();
 
         let s: Vec<f64> = vec![
             3.8589375, 3.4396766, 2.6487176, 2.2317399, 1.5165054, 0.8109055, 0.2706515,
@@ -647,7 +651,8 @@ mod tests {
                 0.73034065,
                 -0.43965505,
             ],
-        ]);
+        ])
+        .unwrap();
 
         let V = DenseMatrix::from_2d_array(&[
             &[
@@ -707,7 +712,8 @@ mod tests {
                 0.1654796,
                 -0.32346758,
             ],
-        ]);
+        ])
+        .unwrap();
 
         let svd = A.svd().unwrap();
 
@@ -723,10 +729,11 @@ mod tests {
     )]
     #[test]
     fn solve() {
-        let a = DenseMatrix::from_2d_array(&[&[0.9, 0.4, 0.7], &[0.4, 0.5, 0.3], &[0.7, 0.3, 0.8]]);
+        let a = DenseMatrix::from_2d_array(&[&[0.9, 0.4, 0.7], &[0.4, 0.5, 0.3], &[0.7, 0.3, 0.8]])
-        let b = DenseMatrix::from_2d_array(&[&[0.5, 0.2], &[0.5, 0.8], &[0.5, 0.3]]);
+            .unwrap();
+        let b = DenseMatrix::from_2d_array(&[&[0.5, 0.2], &[0.5, 0.8], &[0.5, 0.3]]).unwrap();
         let expected_w =
-            DenseMatrix::from_2d_array(&[&[-0.20, -1.28], &[0.87, 2.22], &[0.47, 0.66]]);
+            DenseMatrix::from_2d_array(&[&[-0.20, -1.28], &[0.87, 2.22], &[0.47, 0.66]]).unwrap();
         let w = a.svd_solve_mut(b).unwrap();
         assert!(relative_eq!(w, expected_w, epsilon = 1e-2));
     }
@@ -737,7 +744,8 @@ mod tests {
     )]
     #[test]
     fn decompose_restore() {
-        let a = DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0, 4.0], &[5.0, 6.0, 7.0, 8.0]]);
+        let a =
+            DenseMatrix::from_2d_array(&[&[1.0, 2.0, 3.0, 4.0], &[5.0, 6.0, 7.0, 8.0]]).unwrap();
         let svd = a.svd().unwrap();
         let u: &DenseMatrix<f32> = &svd.U; //U
         let v: &DenseMatrix<f32> = &svd.V; // V

src/linear/bg_solver.rs

@@ -12,7 +12,8 @@
 //! pub struct BGSolver {}
 //! impl<'a, T: FloatNumber, X: Array2<T>> BiconjugateGradientSolver<'a, T, X> for BGSolver {}
 //!
-//! let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0., 11.]]);
+//! let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0.,
+//! 11.]]).unwrap();
 //! let b = vec![40., 51., 28.];
 //! let expected = vec![1.0, 2.0, 3.0];
 //! let mut x = Vec::zeros(3);
@@ -158,7 +159,8 @@ mod tests {
 
     #[test]
     fn bg_solver() {
-        let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0., 11.]]);
+        let a = DenseMatrix::from_2d_array(&[&[25., 15., -5.], &[15., 18., 0.], &[-5., 0., 11.]])
+            .unwrap();
         let b = vec![40., 51., 28.];
         let expected = [1.0, 2.0, 3.0];
 

src/linear/elastic_net.rs

@@ -38,7 +38,7 @@
 //!               &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
 //!               &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
 //!               &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-//!          ]);
+//!          ]).unwrap();
 //!
 //! let y: Vec<f64> = vec![83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0,
 //!           100.0, 101.2, 104.6, 108.4, 110.8, 112.6, 114.2, 115.7, 116.9];
@@ -511,7 +511,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
@@ -562,7 +563,8 @@ mod tests {
             &[17.0, 1918.0, 1.4054969025700674],
             &[18.0, 1929.0, 1.3271699396384906],
             &[19.0, 1915.0, 1.1373332337674806],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<f64> = vec![
             1.48, 2.72, 4.52, 5.72, 5.25, 4.07, 3.75, 4.75, 6.77, 4.72, 6.78, 6.79, 8.3, 7.42,
@@ -627,7 +629,7 @@ mod tests {
     //         &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
     //         &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
     //         &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-    //     ]);
+    //     ]).unwrap();
 
     //     let y = vec![
     //         83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,

src/linear/lasso.rs

@@ -418,7 +418,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,

src/linear/linear_regression.rs

@@ -40,7 +40,7 @@
 //!               &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
 //!               &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
 //!               &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-//!          ]);
+//!          ]).unwrap();
 //!
 //! let y: Vec<f64> = vec![83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0,
 //!           100.0, 101.2, 104.6, 108.4, 110.8, 112.6, 114.2, 115.7, 116.9];
@@ -341,7 +341,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8,
@@ -393,7 +394,7 @@ mod tests {
     //         &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
     //         &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
     //         &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-    //     ]);
+    //     ]).unwrap();
 
     //     let y = vec![
     //         83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,

src/linear/logistic_regression.rs

@@ -35,7 +35,7 @@
 //!           &[4.9, 2.4, 3.3, 1.0],
 //!           &[6.6, 2.9, 4.6, 1.3],
 //!           &[5.2, 2.7, 3.9, 1.4],
-//!           ]);
+//!           ]).unwrap();
 //! let y: Vec<i32> = vec![
 //!           0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 //! ];
@@ -416,7 +416,7 @@ impl<TX: Number + FloatNumber + RealNumber, TY: Number + Ord, X: Array2<TX>, Y:
     /// Fits Logistic Regression to your data.
     /// * `x` - _NxM_ matrix with _N_ observations and _M_ features in each observation.
     /// * `y` - target class values
-    /// * `parameters` - other parameters, use `Default::default()` to set parameters to default values.    
+    /// * `parameters` - other parameters, use `Default::default()` to set parameters to default values.
     pub fn fit(
         x: &X,
         y: &Y,
@@ -611,7 +611,8 @@ mod tests {
             &[10., -2.],
             &[8., 2.],
             &[9., 0.],
-        ]);
+        ])
+        .unwrap();
 
         let y = vec![0, 0, 1, 1, 2, 1, 1, 0, 0, 2, 1, 1, 0, 0, 1];
 
@@ -671,7 +672,8 @@ mod tests {
             &[10., -2.],
             &[8., 2.],
             &[9., 0.],
-        ]);
+        ])
+        .unwrap();
 
         let y = vec![0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1];
 
@@ -733,7 +735,8 @@ mod tests {
             &[10., -2.],
             &[8., 2.],
             &[9., 0.],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<i32> = vec![0, 0, 1, 1, 2, 1, 1, 0, 0, 2, 1, 1, 0, 0, 1];
 
         let lr = LogisticRegression::fit(&x, &y, Default::default()).unwrap();
@@ -818,37 +821,41 @@ mod tests {
         assert!(reg_coeff_sum < coeff);
     }
 
-    // TODO: serialization for the new DenseMatrix needs to be implemented
+    //TODO: serialization for the new DenseMatrix needs to be implemented
-    // #[cfg_attr(all(target_arch = "wasm32", not(target_os = "wasi")), wasm_bindgen_test::wasm_bindgen_test)]
+    #[cfg_attr(
-    // #[test]
+        all(target_arch = "wasm32", not(target_os = "wasi")),
-    // #[cfg(feature = "serde")]
+        wasm_bindgen_test::wasm_bindgen_test
-    // fn serde() {
+    )]
-    //     let x = DenseMatrix::from_2d_array(&[
+    #[test]
-    //         &[1., -5.],
+    #[cfg(feature = "serde")]
-    //         &[2., 5.],
+    fn serde() {
-    //         &[3., -2.],
+        let x: DenseMatrix<f64> = DenseMatrix::from_2d_array(&[
-    //         &[1., 2.],
+            &[1., -5.],
-    //         &[2., 0.],
+            &[2., 5.],
-    //         &[6., -5.],
+            &[3., -2.],
-    //         &[7., 5.],
+            &[1., 2.],
-    //         &[6., -2.],
+            &[2., 0.],
-    //         &[7., 2.],
+            &[6., -5.],
-    //         &[6., 0.],
+            &[7., 5.],
-    //         &[8., -5.],
+            &[6., -2.],
-    //         &[9., 5.],
+            &[7., 2.],
-    //         &[10., -2.],
+            &[6., 0.],
-    //         &[8., 2.],
+            &[8., -5.],
-    //         &[9., 0.],
+            &[9., 5.],
-    //     ]);
+            &[10., -2.],
-    //     let y: Vec<i32> = vec![0, 0, 1, 1, 2, 1, 1, 0, 0, 2, 1, 1, 0, 0, 1];
+            &[8., 2.],
+            &[9., 0.],
+        ])
+        .unwrap();
+        let y: Vec<i32> = vec![0, 0, 1, 1, 2, 1, 1, 0, 0, 2, 1, 1, 0, 0, 1];
 
-    //     let lr = LogisticRegression::fit(&x, &y, Default::default()).unwrap();
+        let lr = LogisticRegression::fit(&x, &y, Default::default()).unwrap();
 
-    //     let deserialized_lr: LogisticRegression<f64, i32, DenseMatrix<f64>, Vec<i32>> =
+        let deserialized_lr: LogisticRegression<f64, i32, DenseMatrix<f64>, Vec<i32>> =
-    //         serde_json::from_str(&serde_json::to_string(&lr).unwrap()).unwrap();
+            serde_json::from_str(&serde_json::to_string(&lr).unwrap()).unwrap();
 
-    //     assert_eq!(lr, deserialized_lr);
+        assert_eq!(lr, deserialized_lr);
-    // }
+    }
 
     #[cfg_attr(
         all(target_arch = "wasm32", not(target_os = "wasi")),
@@ -877,7 +884,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<i32> = vec![0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 
         let lr = LogisticRegression::fit(&x, &y, Default::default()).unwrap();
@@ -899,4 +907,46 @@ mod tests {
 
         assert!(reg_coeff_sum < coeff);
     }
+    #[cfg_attr(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        wasm_bindgen_test::wasm_bindgen_test
+    )]
+    #[test]
+    fn lr_fit_predict_random() {
+        let x: DenseMatrix<f32> = DenseMatrix::rand(52181, 94);
+        let y1: Vec<i32> = vec![1; 2181];
+        let y2: Vec<i32> = vec![0; 50000];
+        let y: Vec<i32> = y1.into_iter().chain(y2.into_iter()).collect();
+
+        let lr = LogisticRegression::fit(&x, &y, Default::default()).unwrap();
+        let lr_reg = LogisticRegression::fit(
+            &x,
+            &y,
+            LogisticRegressionParameters::default().with_alpha(1.0),
+        )
+        .unwrap();
+
+        let y_hat = lr.predict(&x).unwrap();
+        let y_hat_reg = lr_reg.predict(&x).unwrap();
+
+        assert_eq!(y.len(), y_hat.len());
+        assert_eq!(y.len(), y_hat_reg.len());
+    }
+
+    #[test]
+    fn test_logit() {
+        let x: &DenseMatrix<f64> = &DenseMatrix::rand(52181, 94);
+        let y1: Vec<u32> = vec![1; 2181];
+        let y2: Vec<u32> = vec![0; 50000];
+        let y: &Vec<u32> = &(y1.into_iter().chain(y2.into_iter()).collect());
+        println!("y vec height: {:?}", y.len());
+        println!("x matrix shape: {:?}", x.shape());
+
+        let lr = LogisticRegression::fit(x, y, Default::default()).unwrap();
+        let y_hat = lr.predict(&x).unwrap();
+
+        println!("y_hat shape: {:?}", y_hat.shape());
+
+        assert_eq!(y_hat.shape(), 52181);
+    }
 }

src/linear/ridge_regression.rs

@@ -40,7 +40,7 @@
 //!               &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
 //!               &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
 //!               &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-//!          ]);
+//!          ]).unwrap();
 //!
 //! let y: Vec<f64> = vec![83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0,
 //!           100.0, 101.2, 104.6, 108.4, 110.8, 112.6, 114.2, 115.7, 116.9];
@@ -455,7 +455,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
@@ -513,7 +514,7 @@ mod tests {
     //         &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
     //         &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
     //         &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-    //     ]);
+    //     ]).unwrap();
 
     //     let y = vec![
     //         83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,

src/metrics/distance/mahalanobis.rs

@@ -25,7 +25,7 @@
 //!                   &[68., 590., 37.],
 //!                   &[69., 660., 46.],
 //!                   &[73., 600., 55.],
-//! ]);
+//! ]).unwrap();
 //!
 //! let a = data.mean_by(0);
 //! let b = vec![66., 640., 44.];
@@ -151,7 +151,8 @@ mod tests {
             &[68., 590., 37.],
             &[69., 660., 46.],
             &[73., 600., 55.],
-        ]);
+        ])
+        .unwrap();
 
         let a = data.mean_by(0);
         let b = vec![66., 640., 44.];

src/metrics/mod.rs

@@ -37,7 +37,7 @@
 //!             &[4.9, 2.4, 3.3, 1.0],
 //!             &[6.6, 2.9, 4.6, 1.3],
 //!             &[5.2, 2.7, 3.9, 1.4],
-//!   ]);
+//!   ]).unwrap();
 //! let y: Vec<i8> = vec![
 //!             0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 //!   ];

src/model_selection/mod.rs

@@ -36,7 +36,7 @@
 //!           &[4.9, 2.4, 3.3, 1.0],
 //!           &[6.6, 2.9, 4.6, 1.3],
 //!           &[5.2, 2.7, 3.9, 1.4],
-//!           ]);
+//!           ]).unwrap();
 //! let y: Vec<f64> = vec![
 //!           0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1.,
 //! ];
@@ -84,7 +84,7 @@
 //!           &[4.9, 2.4, 3.3, 1.0],
 //!           &[6.6, 2.9, 4.6, 1.3],
 //!           &[5.2, 2.7, 3.9, 1.4],
-//!           ]);
+//!           ]).unwrap();
 //! let y: Vec<i32> = vec![
 //!           0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 //! ];
@@ -396,7 +396,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 
         let cv = KFold {
@@ -441,7 +442,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
         let y = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
             114.2, 115.7, 116.9,
@@ -489,7 +491,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
             114.2, 115.7, 116.9,
@@ -539,7 +542,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<i32> = vec![0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 
         let cv = KFold::default().with_n_splits(3);

src/naive_bayes/bernoulli.rs

@@ -19,14 +19,14 @@
 //!           &[0, 1, 0, 0, 1, 0],
 //!           &[0, 1, 0, 1, 0, 0],
 //!           &[0, 1, 1, 0, 0, 1],
-//! ]);
+//! ]).unwrap();
 //! let y: Vec<u32> = vec![0, 0, 0, 1];
 //!
 //! let nb = BernoulliNB::fit(&x, &y, Default::default()).unwrap();
 //!
 //! // Testing data point is:
 //! // Chinese Chinese Chinese Tokyo Japan
-//! let x_test = DenseMatrix::from_2d_array(&[&[0, 1, 1, 0, 0, 1]]);
+//! let x_test = DenseMatrix::from_2d_array(&[&[0, 1, 1, 0, 0, 1]]).unwrap();
 //! let y_hat = nb.predict(&x_test).unwrap();
 //! ```
 //!
@@ -527,7 +527,8 @@ mod tests {
             &[0.0, 1.0, 0.0, 0.0, 1.0, 0.0],
             &[0.0, 1.0, 0.0, 1.0, 0.0, 0.0],
             &[0.0, 1.0, 1.0, 0.0, 0.0, 1.0],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![0, 0, 0, 1];
         let bnb = BernoulliNB::fit(&x, &y, Default::default()).unwrap();
 
@@ -558,7 +559,7 @@ mod tests {
 
         // Testing data point is:
         //  Chinese Chinese Chinese Tokyo Japan
-        let x_test = DenseMatrix::from_2d_array(&[&[0.0, 1.0, 1.0, 0.0, 0.0, 1.0]]);
+        let x_test = DenseMatrix::from_2d_array(&[&[0.0, 1.0, 1.0, 0.0, 0.0, 1.0]]).unwrap();
         let y_hat = bnb.predict(&x_test).unwrap();
 
         assert_eq!(y_hat, &[1]);
@@ -586,7 +587,8 @@ mod tests {
             &[2, 0, 3, 3, 1, 2, 0, 2, 4, 1],
             &[2, 4, 0, 4, 2, 4, 1, 3, 1, 4],
             &[0, 2, 2, 3, 4, 0, 4, 4, 4, 4],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![2, 2, 0, 0, 0, 2, 1, 1, 0, 1, 0, 0, 2, 0, 2];
         let bnb = BernoulliNB::fit(&x, &y, Default::default()).unwrap();
 
@@ -643,7 +645,8 @@ mod tests {
             &[0, 1, 0, 0, 1, 0],
             &[0, 1, 0, 1, 0, 0],
             &[0, 1, 1, 0, 0, 1],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![0, 0, 0, 1];
 
         let bnb = BernoulliNB::fit(&x, &y, Default::default()).unwrap();

src/naive_bayes/categorical.rs

@@ -24,7 +24,7 @@
 //!              &[3, 4, 2, 4],
 //!              &[0, 3, 1, 2],
 //!              &[0, 4, 1, 2],
-//!          ]);
+//!          ]).unwrap();
 //! let y: Vec<u32> = vec![0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0];
 //!
 //! let nb = CategoricalNB::fit(&x, &y, Default::default()).unwrap();
@@ -455,7 +455,8 @@ mod tests {
             &[1, 1, 1, 1],
             &[1, 2, 0, 0],
             &[2, 1, 1, 1],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0];
 
         let cnb = CategoricalNB::fit(&x, &y, Default::default()).unwrap();
@@ -513,7 +514,7 @@ mod tests {
             ]
         );
 
-        let x_test = DenseMatrix::from_2d_array(&[&[0, 2, 1, 0], &[2, 2, 0, 0]]);
+        let x_test = DenseMatrix::from_2d_array(&[&[0, 2, 1, 0], &[2, 2, 0, 0]]).unwrap();
         let y_hat = cnb.predict(&x_test).unwrap();
         assert_eq!(y_hat, vec![0, 1]);
     }
@@ -539,7 +540,8 @@ mod tests {
             &[3, 4, 2, 4],
             &[0, 3, 1, 2],
             &[0, 4, 1, 2],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0];
 
         let cnb = CategoricalNB::fit(&x, &y, Default::default()).unwrap();
@@ -571,7 +573,8 @@ mod tests {
             &[3, 4, 2, 4],
             &[0, 3, 1, 2],
             &[0, 4, 1, 2],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<u32> = vec![0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0];
         let cnb = CategoricalNB::fit(&x, &y, Default::default()).unwrap();

src/naive_bayes/gaussian.rs

@@ -16,7 +16,7 @@
 //!              &[ 1.,  1.],
 //!              &[ 2.,  1.],
 //!              &[ 3.,  2.],
-//!          ]);
+//!          ]).unwrap();
 //! let y: Vec<u32> = vec![1, 1, 1, 2, 2, 2];
 //!
 //! let nb = GaussianNB::fit(&x, &y, Default::default()).unwrap();
@@ -395,7 +395,8 @@ mod tests {
             &[1., 1.],
             &[2., 1.],
             &[3., 2.],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![1, 1, 1, 2, 2, 2];
 
         let gnb = GaussianNB::fit(&x, &y, Default::default()).unwrap();
@@ -435,7 +436,8 @@ mod tests {
             &[1., 1.],
             &[2., 1.],
             &[3., 2.],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![1, 1, 1, 2, 2, 2];
 
         let priors = vec![0.3, 0.7];
@@ -462,7 +464,8 @@ mod tests {
             &[1., 1.],
             &[2., 1.],
             &[3., 2.],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![1, 1, 1, 2, 2, 2];
 
         let gnb = GaussianNB::fit(&x, &y, Default::default()).unwrap();

src/naive_bayes/mod.rs

@@ -169,7 +169,7 @@ mod tests {
 
     #[test]
     fn test_predict() {
-        let matrix = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]);
+        let matrix = DenseMatrix::from_2d_array(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]).unwrap();
 
         let val = vec![];
         match Model::fit(TestDistribution(&val)).unwrap().predict(&matrix) {

src/naive_bayes/multinomial.rs

@@ -20,13 +20,13 @@
 //!                   &[0, 2, 0, 0, 1, 0],
 //!                   &[0, 1, 0, 1, 0, 0],
 //!                   &[0, 1, 1, 0, 0, 1],
-//!         ]);
+//!         ]).unwrap();
 //! let y: Vec<u32> = vec![0, 0, 0, 1];
 //! let nb = MultinomialNB::fit(&x, &y, Default::default()).unwrap();
 //!
 //! // Testing data point is:
 //! //  Chinese Chinese Chinese Tokyo Japan
-//! let x_test = DenseMatrix::from_2d_array(&[&[0, 3, 1, 0, 0, 1]]);
+//! let x_test = DenseMatrix::from_2d_array(&[&[0, 3, 1, 0, 0, 1]]).unwrap();
 //! let y_hat = nb.predict(&x_test).unwrap();
 //! ```
 //!
@@ -433,7 +433,8 @@ mod tests {
             &[0, 2, 0, 0, 1, 0],
             &[0, 1, 0, 1, 0, 0],
             &[0, 1, 1, 0, 0, 1],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![0, 0, 0, 1];
         let mnb = MultinomialNB::fit(&x, &y, Default::default()).unwrap();
 
@@ -467,7 +468,7 @@ mod tests {
 
         // Testing data point is:
         //  Chinese Chinese Chinese Tokyo Japan
-        let x_test = DenseMatrix::<u32>::from_2d_array(&[&[0, 3, 1, 0, 0, 1]]);
+        let x_test = DenseMatrix::<u32>::from_2d_array(&[&[0, 3, 1, 0, 0, 1]]).unwrap();
         let y_hat = mnb.predict(&x_test).unwrap();
 
         assert_eq!(y_hat, &[0]);
@@ -495,7 +496,8 @@ mod tests {
             &[2, 0, 3, 3, 1, 2, 0, 2, 4, 1],
             &[2, 4, 0, 4, 2, 4, 1, 3, 1, 4],
             &[0, 2, 2, 3, 4, 0, 4, 4, 4, 4],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![2, 2, 0, 0, 0, 2, 1, 1, 0, 1, 0, 0, 2, 0, 2];
         let nb = MultinomialNB::fit(&x, &y, Default::default()).unwrap();
 
@@ -554,7 +556,8 @@ mod tests {
             &[0, 1, 0, 0, 1, 0],
             &[0, 1, 0, 1, 0, 0],
             &[0, 1, 1, 0, 0, 1],
-        ]);
+        ])
+        .unwrap();
         let y = vec![0, 0, 0, 1];
 
         let mnb = MultinomialNB::fit(&x, &y, Default::default()).unwrap();

src/neighbors/knn_classifier.rs

@@ -22,7 +22,7 @@
 //!     &[3., 4.],
 //!     &[5., 6.],
 //!     &[7., 8.],
-//! &[9., 10.]]);
+//! &[9., 10.]]).unwrap();
 //! let y = vec![2, 2, 2, 3, 3]; //your class labels
 //!
 //! let knn = KNNClassifier::fit(&x, &y, Default::default()).unwrap();
@@ -211,7 +211,7 @@ impl<TX: Number, TY: Number + Ord, X: Array2<TX>, Y: Array1<TY>, D: Distance<Vec
 {
     /// Fits KNN classifier to a NxM matrix where N is number of samples and M is number of features.
     /// * `x` - training data
-    /// * `y` - vector with target values (classes) of length N    
+    /// * `y` - vector with target values (classes) of length N
     /// * `parameters` - additional parameters like search algorithm and k
     pub fn fit(
         x: &X,
@@ -311,7 +311,8 @@ mod tests {
     #[test]
     fn knn_fit_predict() {
         let x =
-            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]]);
+            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]])
+                .unwrap();
         let y = vec![2, 2, 2, 3, 3];
         let knn = KNNClassifier::fit(&x, &y, Default::default()).unwrap();
         let y_hat = knn.predict(&x).unwrap();
@@ -325,7 +326,7 @@ mod tests {
     )]
     #[test]
     fn knn_fit_predict_weighted() {
-        let x = DenseMatrix::from_2d_array(&[&[1.], &[2.], &[3.], &[4.], &[5.]]);
+        let x = DenseMatrix::from_2d_array(&[&[1.], &[2.], &[3.], &[4.], &[5.]]).unwrap();
         let y = vec![2, 2, 2, 3, 3];
         let knn = KNNClassifier::fit(
             &x,
@@ -336,7 +337,9 @@ mod tests {
                 .with_weight(KNNWeightFunction::Distance),
         )
         .unwrap();
-        let y_hat = knn.predict(&DenseMatrix::from_2d_array(&[&[4.1]])).unwrap();
+        let y_hat = knn
+            .predict(&DenseMatrix::from_2d_array(&[&[4.1]]).unwrap())
+            .unwrap();
         assert_eq!(vec![3], y_hat);
     }
 
@@ -348,7 +351,8 @@ mod tests {
     #[cfg(feature = "serde")]
     fn serde() {
         let x =
-            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]]);
+            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]])
+                .unwrap();
         let y = vec![2, 2, 2, 3, 3];
 
         let knn = KNNClassifier::fit(&x, &y, Default::default()).unwrap();

src/neighbors/knn_regressor.rs

@@ -24,7 +24,7 @@
 //!     &[2., 2.],
 //!     &[3., 3.],
 //!     &[4., 4.],
-//!     &[5., 5.]]);
+//!     &[5., 5.]]).unwrap();
 //! let y = vec![1., 2., 3., 4., 5.]; //your target values
 //!
 //! let knn = KNNRegressor::fit(&x, &y, Default::default()).unwrap();
@@ -207,7 +207,7 @@ impl<TX: Number, TY: Number, X: Array2<TX>, Y: Array1<TY>, D: Distance<Vec<TX>>>
 {
     /// Fits KNN regressor to a NxM matrix where N is number of samples and M is number of features.
     /// * `x` - training data
-    /// * `y` - vector with real values    
+    /// * `y` - vector with real values
     /// * `parameters` - additional parameters like search algorithm and k
     pub fn fit(
         x: &X,
@@ -295,7 +295,8 @@ mod tests {
     #[test]
     fn knn_fit_predict_weighted() {
         let x =
-            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]]);
+            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]])
+                .unwrap();
         let y: Vec<f64> = vec![1., 2., 3., 4., 5.];
         let y_exp = [1., 2., 3., 4., 5.];
         let knn = KNNRegressor::fit(
@@ -322,7 +323,8 @@ mod tests {
     #[test]
     fn knn_fit_predict_uniform() {
         let x =
-            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]]);
+            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]])
+                .unwrap();
         let y: Vec<f64> = vec![1., 2., 3., 4., 5.];
         let y_exp = [2., 2., 3., 4., 4.];
         let knn = KNNRegressor::fit(&x, &y, Default::default()).unwrap();
@@ -341,7 +343,8 @@ mod tests {
     #[cfg(feature = "serde")]
     fn serde() {
         let x =
-            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]]);
+            DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.], &[7., 8.], &[9., 10.]])
+                .unwrap();
         let y = vec![1., 2., 3., 4., 5.];
 
         let knn = KNNRegressor::fit(&x, &y, Default::default()).unwrap();

src/preprocessing/categorical.rs

@@ -12,7 +12,7 @@
 //!         &[1.5, 2.0, 1.5, 4.0],
 //!         &[1.5, 1.0, 1.5, 5.0],
 //!         &[1.5, 2.0, 1.5, 6.0],
-//!   ]);
+//!   ]).unwrap();
 //! let encoder_params = OneHotEncoderParams::from_cat_idx(&[1, 3]);
 //! // Infer number of categories from data and return a reusable encoder
 //! let encoder = OneHotEncoder::fit(&data, encoder_params).unwrap();
@@ -240,14 +240,16 @@ mod tests {
             &[2.0, 1.5, 4.0],
             &[1.0, 1.5, 5.0],
             &[2.0, 1.5, 6.0],
-        ]);
+        ])
+        .unwrap();
 
         let oh_enc = DenseMatrix::from_2d_array(&[
             &[1.0, 0.0, 1.5, 1.0, 0.0, 0.0, 0.0],
             &[0.0, 1.0, 1.5, 0.0, 1.0, 0.0, 0.0],
             &[1.0, 0.0, 1.5, 0.0, 0.0, 1.0, 0.0],
             &[0.0, 1.0, 1.5, 0.0, 0.0, 0.0, 1.0],
-        ]);
+        ])
+        .unwrap();
 
         (orig, oh_enc)
     }
@@ -259,14 +261,16 @@ mod tests {
             &[1.5, 2.0, 1.5, 4.0],
             &[1.5, 1.0, 1.5, 5.0],
             &[1.5, 2.0, 1.5, 6.0],
-        ]);
+        ])
+        .unwrap();
 
         let oh_enc = DenseMatrix::from_2d_array(&[
             &[1.5, 1.0, 0.0, 1.5, 1.0, 0.0, 0.0, 0.0],
             &[1.5, 0.0, 1.0, 1.5, 0.0, 1.0, 0.0, 0.0],
             &[1.5, 1.0, 0.0, 1.5, 0.0, 0.0, 1.0, 0.0],
             &[1.5, 0.0, 1.0, 1.5, 0.0, 0.0, 0.0, 1.0],
-        ]);
+        ])
+        .unwrap();
 
         (orig, oh_enc)
     }
@@ -334,7 +338,8 @@ mod tests {
             &[2.0, 1.5, 4.0],
             &[1.0, 1.5, 5.0],
             &[2.0, 1.5, 6.0],
-        ]);
+        ])
+        .unwrap();
 
         let params = OneHotEncoderParams::from_cat_idx(&[1]);
         let result = OneHotEncoder::fit(&m, params);

src/preprocessing/numerical.rs

@@ -11,7 +11,7 @@
 //!     vec![0.0, 0.0],
 //!     vec![1.0, 1.0],
 //!     vec![1.0, 1.0],
-//! ]);
+//! ]).unwrap();
 //!
 //! let standard_scaler =
 //! numerical::StandardScaler::fit(&data, numerical::StandardScalerParameters::default())
@@ -24,7 +24,7 @@
 //!         vec![-1.0, -1.0],
 //!         vec![1.0, 1.0],
 //!         vec![1.0, 1.0],
-//!     ])
+//!     ]).unwrap()
 //! );
 //! ```
 use std::marker::PhantomData;
@@ -197,15 +197,18 @@ mod tests {
         fn combine_three_columns() {
             assert_eq!(
                 build_matrix_from_columns(vec![
-                    DenseMatrix::from_2d_vec(&[vec![1.0], vec![1.0], vec![1.0]]),
+                    DenseMatrix::from_2d_vec(&vec![vec![1.0], vec![1.0], vec![1.0],]).unwrap(),
-                    DenseMatrix::from_2d_vec(&[vec![2.0], vec![2.0], vec![2.0]]),
+                    DenseMatrix::from_2d_vec(&vec![vec![2.0], vec![2.0], vec![2.0],]).unwrap(),
-                    DenseMatrix::from_2d_vec(&[vec![3.0], vec![3.0], vec![3.0]])
+                    DenseMatrix::from_2d_vec(&vec![vec![3.0], vec![3.0], vec![3.0],]).unwrap()
                 ]),
-                Some(DenseMatrix::from_2d_vec(&[
+                Some(
-                    vec![1.0, 2.0, 3.0],
+                    DenseMatrix::from_2d_vec(&vec![
-                    vec![1.0, 2.0, 3.0],
+                        vec![1.0, 2.0, 3.0],
-                    vec![1.0, 2.0, 3.0]
+                        vec![1.0, 2.0, 3.0],
-                ]))
+                        vec![1.0, 2.0, 3.0]
+                    ])
+                    .unwrap()
+                )
             )
         }
 
@@ -287,13 +290,15 @@ mod tests {
         /// sklearn.
         #[test]
         fn fit_transform_random_values() {
-            let transformed_values =
+            let transformed_values = fit_transform_with_default_standard_scaler(
-                fit_transform_with_default_standard_scaler(&DenseMatrix::from_2d_array(&[
+                &DenseMatrix::from_2d_array(&[
                     &[0.1004222429, 0.2194113576, 0.9310663354, 0.3313593793],
                     &[0.2045493861, 0.1683865411, 0.5071506765, 0.7257355264],
                     &[0.5708488802, 0.1846414616, 0.9590802982, 0.5591871046],
                     &[0.8387612750, 0.5754861361, 0.5537109852, 0.1077646442],
-                ]));
+                ])
+                .unwrap(),
+            );
             println!("{transformed_values}");
             assert!(transformed_values.approximate_eq(
                 &DenseMatrix::from_2d_array(&[
@@ -301,7 +306,8 @@ mod tests {
                     &[-0.7615464283, -0.7076698384, -1.1075452562, 1.2632979631],
                     &[0.4832504303, -0.6106747444, 1.0630075435, 0.5494084257],
                     &[1.3936980634, 1.7215431158, -0.8839228078, -1.3855590021],
-                ]),
+                ])
+                .unwrap(),
                 1.0
             ))
         }
@@ -310,13 +316,10 @@ mod tests {
         #[test]
         fn fit_transform_with_zero_variance() {
             assert_eq!(
-                fit_transform_with_default_standard_scaler(&DenseMatrix::from_2d_array(&[
+                fit_transform_with_default_standard_scaler(
-                    &[1.0],
+                    &DenseMatrix::from_2d_array(&[&[1.0], &[1.0], &[1.0], &[1.0]]).unwrap()
-                    &[1.0],
+                ),
-                    &[1.0],
+                DenseMatrix::from_2d_array(&[&[0.0], &[0.0], &[0.0], &[0.0]]).unwrap(),
-                    &[1.0]
-                ])),
-                DenseMatrix::from_2d_array(&[&[0.0], &[0.0], &[0.0], &[0.0]]),
                 "When scaling values with zero variance, zero is expected as return value"
             )
         }
@@ -331,7 +334,8 @@ mod tests {
                         &[1.0, 2.0, 5.0],
                         &[1.0, 1.0, 1.0],
                         &[1.0, 2.0, 5.0]
-                    ]),
+                    ])
+                    .unwrap(),
                     StandardScalerParameters::default(),
                 ),
                 Ok(StandardScaler {
@@ -354,7 +358,8 @@ mod tests {
                     &[0.2045493861, 0.1683865411, 0.5071506765, 0.7257355264],
                     &[0.5708488802, 0.1846414616, 0.9590802982, 0.5591871046],
                     &[0.8387612750, 0.5754861361, 0.5537109852, 0.1077646442],
-                ]),
+                ])
+                .unwrap(),
                 StandardScalerParameters::default(),
             )
             .unwrap();
@@ -364,17 +369,18 @@ mod tests {
                 vec![0.42864544605, 0.2869813741, 0.737752073825, 0.431011663625],
             );
 
-            assert!(
+            assert!(&DenseMatrix::<f64>::from_2d_vec(&vec![fitted_scaler.stds])
-                &DenseMatrix::<f64>::from_2d_vec(&[fitted_scaler.stds]).approximate_eq(
+                .unwrap()
+                .approximate_eq(
                     &DenseMatrix::from_2d_array(&[&[
                         0.29426447500954,
                         0.16758497615485,
                         0.20820945786863,
                         0.23329718831165
-                    ],]),
+                    ],])
+                    .unwrap(),
                     0.00000000000001
-                )
+                ))
-            )
         }
 
         /// If `with_std` is set to `false` the values should not be
@@ -392,8 +398,9 @@ mod tests {
             };
 
             assert_eq!(
-                standard_scaler.transform(&DenseMatrix::from_2d_array(&[&[0.0, 2.0], &[2.0, 4.0]])),
+                standard_scaler
-                Ok(DenseMatrix::from_2d_array(&[&[-1.0, -1.0], &[1.0, 1.0]]))
+                    .transform(&DenseMatrix::from_2d_array(&[&[0.0, 2.0], &[2.0, 4.0]]).unwrap()),
+                Ok(DenseMatrix::from_2d_array(&[&[-1.0, -1.0], &[1.0, 1.0]]).unwrap())
             )
         }
 
@@ -413,8 +420,8 @@ mod tests {
 
             assert_eq!(
                 standard_scaler
-                    .transform(&DenseMatrix::from_2d_array(&[&[0.0, 9.0], &[4.0, 12.0]])),
+                    .transform(&DenseMatrix::from_2d_array(&[&[0.0, 9.0], &[4.0, 12.0]]).unwrap()),
-                Ok(DenseMatrix::from_2d_array(&[&[0.0, 3.0], &[2.0, 4.0]]))
+                Ok(DenseMatrix::from_2d_array(&[&[0.0, 3.0], &[2.0, 4.0]]).unwrap())
             )
         }
 
@@ -433,7 +440,8 @@ mod tests {
                     &[0.2045493861, 0.1683865411, 0.5071506765, 0.7257355264],
                     &[0.5708488802, 0.1846414616, 0.9590802982, 0.5591871046],
                     &[0.8387612750, 0.5754861361, 0.5537109852, 0.1077646442],
-                ]),
+                ])
+                .unwrap(),
                 StandardScalerParameters::default(),
             )
             .unwrap();
@@ -446,17 +454,18 @@ mod tests {
                 vec![0.42864544605, 0.2869813741, 0.737752073825, 0.431011663625],
             );
 
-            assert!(
+            assert!(&DenseMatrix::from_2d_vec(&vec![deserialized_scaler.stds])
-                &DenseMatrix::from_2d_vec(&vec![deserialized_scaler.stds]).approximate_eq(
+                .unwrap()
+                .approximate_eq(
                     &DenseMatrix::from_2d_array(&[&[
                         0.29426447500954,
                         0.16758497615485,
                         0.20820945786863,
                         0.23329718831165
-                    ],]),
+                    ],])
+                    .unwrap(),
                     0.00000000000001
-                )
+                ))
-            )
         }
     }
 }

src/readers/csv.rs

@@ -238,7 +238,8 @@ mod tests {
                     &[5.1, 3.5, 1.4, 0.2],
                     &[4.9, 3.0, 1.4, 0.2],
                     &[4.7, 3.2, 1.3, 0.2],
-                ]))
+                ])
+                .unwrap())
             )
         }
         #[test]
@@ -261,7 +262,7 @@ mod tests {
                     &[5.1, 3.5, 1.4, 0.2],
                     &[4.9, 3.0, 1.4, 0.2],
                     &[4.7, 3.2, 1.3, 0.2],
-                ]))
+                ]).unwrap())
             )
         }
         #[test]

src/svm/svc.rs

@@ -53,7 +53,7 @@
 //!            &[4.9, 2.4, 3.3, 1.0],
 //!            &[6.6, 2.9, 4.6, 1.3],
 //!            &[5.2, 2.7, 3.9, 1.4],
-//!         ]);
+//!         ]).unwrap();
 //! let y = vec![ -1, -1, -1, -1, -1, -1, -1, -1,
 //!            1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 //!
@@ -957,7 +957,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<i32> = vec![
             -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@@ -983,7 +984,8 @@ mod tests {
     )]
     #[test]
     fn svc_fit_decision_function() {
-        let x = DenseMatrix::from_2d_array(&[&[4.0, 0.0], &[0.0, 4.0], &[8.0, 0.0], &[0.0, 8.0]]);
+        let x = DenseMatrix::from_2d_array(&[&[4.0, 0.0], &[0.0, 4.0], &[8.0, 0.0], &[0.0, 8.0]])
+            .unwrap();
 
         let x2 = DenseMatrix::from_2d_array(&[
             &[3.0, 3.0],
@@ -992,7 +994,8 @@ mod tests {
             &[10.0, 10.0],
             &[1.0, 1.0],
             &[0.0, 0.0],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<i32> = vec![-1, -1, 1, 1];
 
@@ -1045,7 +1048,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<i32> = vec![
             -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@@ -1094,7 +1098,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<i32> = vec![
             -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

src/svm/svr.rs

@@ -44,7 +44,7 @@
 //!               &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
 //!               &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
 //!               &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-//!          ]);
+//!          ]).unwrap();
 //!
 //! let y: Vec<f64> = vec![83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0,
 //!           100.0, 101.2, 104.6, 108.4, 110.8, 112.6, 114.2, 115.7, 116.9];
@@ -640,7 +640,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
@@ -688,7 +689,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
 
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,

src/tree/decision_tree_classifier.rs

@@ -48,7 +48,7 @@
 //!            &[4.9, 2.4, 3.3, 1.0],
 //!            &[6.6, 2.9, 4.6, 1.3],
 //!            &[5.2, 2.7, 3.9, 1.4],
-//!         ]);
+//!         ]).unwrap();
 //! let y = vec![ 0, 0, 0, 0, 0, 0, 0, 0,
 //!            1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 //!
@@ -964,7 +964,8 @@ mod tests {
             &[4.9, 2.4, 3.3, 1.0],
             &[6.6, 2.9, 4.6, 1.3],
             &[5.2, 2.7, 3.9, 1.4],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1];
 
         assert_eq!(
@@ -1031,7 +1032,8 @@ mod tests {
             &[0., 0., 1., 1.],
             &[0., 0., 0., 0.],
             &[0., 0., 0., 1.],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0];
 
         assert_eq!(
@@ -1065,7 +1067,8 @@ mod tests {
             &[0., 0., 1., 1.],
             &[0., 0., 0., 0.],
             &[0., 0., 0., 1.],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<u32> = vec![1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0];
         let tree = DecisionTreeClassifier::fit(&x, &y, Default::default()).unwrap();
         assert_eq!(
@@ -1106,7 +1109,8 @@ mod tests {
             &[0., 0., 1., 1.],
             &[0., 0., 0., 0.],
             &[0., 0., 0., 1.],
-        ]);
+        ])
+        .unwrap();
         let y = vec![1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0];
 
         let tree = DecisionTreeClassifier::fit(&x, &y, Default::default()).unwrap();

src/tree/decision_tree_regressor.rs

@@ -39,7 +39,7 @@
 //!             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
 //!             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
 //!             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-//!        ]);
+//!        ]).unwrap();
 //! let y: Vec<f64> = vec![
 //!             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0,
 //!             101.2, 104.6, 108.4, 110.8, 112.6, 114.2, 115.7, 116.9,
@@ -753,7 +753,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
             114.2, 115.7, 116.9,
@@ -834,7 +835,8 @@ mod tests {
             &[502.601, 393.1, 251.4, 125.368, 1960., 69.564],
             &[518.173, 480.6, 257.2, 127.852, 1961., 69.331],
             &[554.894, 400.7, 282.7, 130.081, 1962., 70.551],
-        ]);
+        ])
+        .unwrap();
         let y: Vec<f64> = vec![
             83.0, 88.5, 88.2, 89.5, 96.2, 98.1, 99.0, 100.0, 101.2, 104.6, 108.4, 110.8, 112.6,
             114.2, 115.7, 116.9,