Lmm/add seeds in more algorithms (#164)

* Provide better output in flaky tests

* feat: add seed parameter to multiple algorithms

* Update changelog

Co-authored-by: Luis Moreno <morenol@users.noreply.github.com>

.github/workflows/ci.yml

@@ -2,23 +2,24 @@ name: CI
 
 on:
   push:
-    branches: [ main, development ]
+    branches: [main, development]
   pull_request:
-    branches: [ development ]
+    branches: [development]
 
 jobs:
   tests:
     runs-on: "${{ matrix.platform.os }}-latest"
     strategy:
       matrix:
-        platform: [
-          { os: "windows", target: "x86_64-pc-windows-msvc" },
-          { os: "windows", target: "i686-pc-windows-msvc" },
-          { os: "ubuntu", target: "x86_64-unknown-linux-gnu" },
-          { os: "ubuntu", target: "i686-unknown-linux-gnu" },
-          { os: "ubuntu", target: "wasm32-unknown-unknown" },
-          { os: "macos", target: "aarch64-apple-darwin" },
-        ]    
+        platform:
+          [
+            { os: "windows", target: "x86_64-pc-windows-msvc" },
+            { os: "windows", target: "i686-pc-windows-msvc" },
+            { os: "ubuntu", target: "x86_64-unknown-linux-gnu" },
+            { os: "ubuntu", target: "i686-unknown-linux-gnu" },
+            { os: "ubuntu", target: "wasm32-unknown-unknown" },
+            { os: "macos", target: "aarch64-apple-darwin" },
+          ]
     env:
       TZ: "/usr/share/zoneinfo/your/location"
     steps:
@@ -40,7 +41,7 @@ jobs:
           default: true
       - name: Install test runner for wasm
         if: matrix.platform.target == 'wasm32-unknown-unknown'
-        run:  curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+        run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
       - name: Stable Build
         uses: actions-rs/cargo@v1
         with:

CHANGELOG.md

@@ -6,6 +6,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## Added
+- Seeds to multiple algorithims that depend on random number generation.
+- Added feature `js` to use WASM in browser
+
+## BREAKING CHANGE
+- Added a new parameter to `train_test_split` to define the seed.
+
+## [0.2.1] - 2022-05-10
+
 ## Added
 - L2 regularization penalty to the Logistic Regression
 - Getters for the naive bayes structs

Cargo.toml

@@ -16,21 +16,25 @@ categories = ["science"]
 default = ["datasets"]
 ndarray-bindings = ["ndarray"]
 nalgebra-bindings = ["nalgebra"]
-datasets = ["rand_distr"]
+datasets = ["rand_distr", "std"]
 fp_bench = ["itertools"]
+std = ["rand/std", "rand/std_rng"]
+# wasm32 only
+js = ["getrandom/js"]
 
 [dependencies]
 ndarray = { version = "0.15", optional = true }
 nalgebra = { version = "0.31", optional = true }
 num-traits = "0.2"
 num = "0.4"
-rand = "0.8"
+rand = { version = "0.8", default-features = false, features = ["small_rng"] }
 rand_distr = { version = "0.4", optional = true }
 serde = { version = "1", features = ["derive"], optional = true }
 itertools = { version = "0.10.3", optional = true }
+cfg-if = "1.0.0"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-getrandom = { version = "0.2", features = ["js"] }
+getrandom = { version = "0.2", optional = true }
 
 [dev-dependencies]
 smartcore = { path = ".", features = ["fp_bench"] }

src/cluster/kmeans.rs

@@ -52,10 +52,10 @@
 //! * ["An Introduction to Statistical Learning", James G., Witten D., Hastie T., Tibshirani R., 10.3.1 K-Means Clustering](http://faculty.marshall.usc.edu/gareth-james/ISL/)
 //! * ["k-means++: The Advantages of Careful Seeding", Arthur D., Vassilvitskii S.](http://ilpubs.stanford.edu:8090/778/1/2006-13.pdf)
 
-use rand::Rng;
 use std::fmt::Debug;
 use std::iter::Sum;
 
+use ::rand::Rng;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
@@ -65,6 +65,7 @@ use crate::error::Failed;
 use crate::linalg::Matrix;
 use crate::math::distance::euclidian::*;
 use crate::math::num::RealNumber;
+use crate::rand::get_rng_impl;
 
 /// K-Means clustering algorithm
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -108,6 +109,9 @@ pub struct KMeansParameters {
     pub k: usize,
     /// Maximum number of iterations of the k-means algorithm for a single run.
     pub max_iter: usize,
+    /// Determines random number generation for centroid initialization.
+    /// Use an int to make the randomness deterministic
+    pub seed: Option<u64>,
 }
 
 impl KMeansParameters {
@@ -128,6 +132,7 @@ impl Default for KMeansParameters {
         KMeansParameters {
             k: 2,
             max_iter: 100,
+            seed: None,
         }
     }
 }
@@ -238,7 +243,7 @@ impl<T: RealNumber + Sum> KMeans<T> {
         let (n, d) = data.shape();
 
         let mut distortion = T::max_value();
-        let mut y = KMeans::kmeans_plus_plus(data, parameters.k);
+        let mut y = KMeans::kmeans_plus_plus(data, parameters.k, parameters.seed);
         let mut size = vec![0; parameters.k];
         let mut centroids = vec![vec![T::zero(); d]; parameters.k];
 
@@ -311,8 +316,8 @@ impl<T: RealNumber + Sum> KMeans<T> {
         Ok(result.to_row_vector())
     }
 
-    fn kmeans_plus_plus<M: Matrix<T>>(data: &M, k: usize) -> Vec<usize> {
-        let mut rng = rand::thread_rng();
+    fn kmeans_plus_plus<M: Matrix<T>>(data: &M, k: usize, seed: Option<u64>) -> Vec<usize> {
+        let mut rng = get_rng_impl(seed);
         let (n, m) = data.shape();
         let mut y = vec![0; n];
         let mut centroid = data.get_row_as_vec(rng.gen_range(0..n));

src/ensemble/random_forest_classifier.rs

@@ -45,8 +45,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-use rand::rngs::StdRng;
-use rand::{Rng, SeedableRng};
+use rand::Rng;
+
 use std::default::Default;
 use std::fmt::Debug;
 
@@ -57,6 +57,7 @@ use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::{Failed, FailedError};
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
+use crate::rand::get_rng_impl;
 use crate::tree::decision_tree_classifier::{
     which_max, DecisionTreeClassifier, DecisionTreeClassifierParameters, SplitCriterion,
 };
@@ -441,7 +442,7 @@ impl<T: RealNumber> RandomForestClassifier<T> {
                 .unwrap()
         });
 
-        let mut rng = StdRng::seed_from_u64(parameters.seed);
+        let mut rng = get_rng_impl(Some(parameters.seed));
         let classes = y_m.unique();
         let k = classes.len();
         let mut trees: Vec<DecisionTreeClassifier<T>> = Vec::new();
@@ -462,9 +463,9 @@ impl<T: RealNumber> RandomForestClassifier<T> {
                 max_depth: parameters.max_depth,
                 min_samples_leaf: parameters.min_samples_leaf,
                 min_samples_split: parameters.min_samples_split,
+                seed: Some(parameters.seed),
             };
-            let tree =
-                DecisionTreeClassifier::fit_weak_learner(x, y, samples, mtry, params, &mut rng)?;
+            let tree = DecisionTreeClassifier::fit_weak_learner(x, y, samples, mtry, params)?;
             trees.push(tree);
         }
 

src/ensemble/random_forest_regressor.rs

@@ -43,8 +43,8 @@
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 
-use rand::rngs::StdRng;
-use rand::{Rng, SeedableRng};
+use rand::Rng;
+
 use std::default::Default;
 use std::fmt::Debug;
 
@@ -55,6 +55,7 @@ use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::{Failed, FailedError};
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
+use crate::rand::get_rng_impl;
 use crate::tree::decision_tree_regressor::{
     DecisionTreeRegressor, DecisionTreeRegressorParameters,
 };
@@ -376,7 +377,7 @@ impl<T: RealNumber> RandomForestRegressor<T> {
             .m
             .unwrap_or((num_attributes as f64).sqrt().floor() as usize);
 
-        let mut rng = StdRng::seed_from_u64(parameters.seed);
+        let mut rng = get_rng_impl(Some(parameters.seed));
         let mut trees: Vec<DecisionTreeRegressor<T>> = Vec::new();
 
         let mut maybe_all_samples: Option<Vec<Vec<bool>>> = Option::None;
@@ -393,9 +394,9 @@ impl<T: RealNumber> RandomForestRegressor<T> {
                 max_depth: parameters.max_depth,
                 min_samples_leaf: parameters.min_samples_leaf,
                 min_samples_split: parameters.min_samples_split,
+                seed: Some(parameters.seed),
             };
-            let tree =
-                DecisionTreeRegressor::fit_weak_learner(x, y, samples, mtry, params, &mut rng)?;
+            let tree = DecisionTreeRegressor::fit_weak_learner(x, y, samples, mtry, params)?;
             trees.push(tree);
         }
 

src/lib.rs

@@ -101,3 +101,5 @@ pub mod readers;
 pub mod svm;
 /// Supervised tree-based learning methods
 pub mod tree;
+
+pub(crate) mod rand;

src/math/num.rs

@@ -9,6 +9,8 @@ use std::iter::{Product, Sum};
 use std::ops::{AddAssign, DivAssign, MulAssign, SubAssign};
 use std::str::FromStr;
 
+use crate::rand::get_rng_impl;
+
 /// Defines real number
 /// <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS_CHTML"></script>
 pub trait RealNumber:
@@ -79,7 +81,7 @@ impl RealNumber for f64 {
     }
 
     fn rand() -> f64 {
-        let mut rng = rand::thread_rng();
+        let mut rng = get_rng_impl(None);
         rng.gen()
     }
 
@@ -124,7 +126,7 @@ impl RealNumber for f32 {
     }
 
     fn rand() -> f32 {
-        let mut rng = rand::thread_rng();
+        let mut rng = get_rng_impl(None);
         rng.gen()
     }
 

src/model_selection/kfold.rs

@@ -5,8 +5,8 @@
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
 use crate::model_selection::BaseKFold;
+use crate::rand::get_rng_impl;
 use rand::seq::SliceRandom;
-use rand::thread_rng;
 
 /// K-Folds cross-validator
 pub struct KFold {
@@ -14,6 +14,9 @@ pub struct KFold {
     pub n_splits: usize, // cannot exceed std::usize::MAX
     /// Whether to shuffle the data before splitting into batches
     pub shuffle: bool,
+    /// When shuffle is True, seed affects the ordering of the indices.
+    /// Which controls the randomness of each fold
+    pub seed: Option<u64>,
 }
 
 impl KFold {
@@ -23,8 +26,10 @@ impl KFold {
 
         // initialise indices
         let mut indices: Vec<usize> = (0..n_samples).collect();
+        let mut rng = get_rng_impl(self.seed);
+
         if self.shuffle {
-            indices.shuffle(&mut thread_rng());
+            indices.shuffle(&mut rng);
         }
         //  return a new array of given shape n_split, filled with each element of n_samples divided by n_splits.
         let mut fold_sizes = vec![n_samples / self.n_splits; self.n_splits];
@@ -66,6 +71,7 @@ impl Default for KFold {
         KFold {
             n_splits: 3,
             shuffle: true,
+            seed: None,
         }
     }
 }
@@ -81,6 +87,12 @@ impl KFold {
         self.shuffle = shuffle;
         self
     }
+
+    /// When shuffle is True, random_state affects the ordering of the indices.
+    pub fn with_seed(mut self, seed: Option<u64>) -> Self {
+        self.seed = seed;
+        self
+    }
 }
 
 /// An iterator over indices that split data into training and test set.
@@ -150,6 +162,7 @@ mod tests {
         let k = KFold {
             n_splits: 3,
             shuffle: false,
+            seed: None,
         };
         let x: DenseMatrix<f64> = DenseMatrix::rand(33, 100);
         let test_indices = k.test_indices(&x);
@@ -165,6 +178,7 @@ mod tests {
         let k = KFold {
             n_splits: 3,
             shuffle: false,
+            seed: None,
         };
         let x: DenseMatrix<f64> = DenseMatrix::rand(34, 100);
         let test_indices = k.test_indices(&x);
@@ -180,6 +194,7 @@ mod tests {
         let k = KFold {
             n_splits: 2,
             shuffle: false,
+            seed: None,
         };
         let x: DenseMatrix<f64> = DenseMatrix::rand(22, 100);
         let test_masks = k.test_masks(&x);
@@ -206,6 +221,7 @@ mod tests {
         let k = KFold {
             n_splits: 2,
             shuffle: false,
+            seed: None,
         };
         let x: DenseMatrix<f64> = DenseMatrix::rand(22, 100);
         let train_test_splits: Vec<(Vec<usize>, Vec<usize>)> = k.split(&x).collect();
@@ -238,6 +254,7 @@ mod tests {
         let k = KFold {
             n_splits: 3,
             shuffle: false,
+            seed: None,
         };
         let x: DenseMatrix<f64> = DenseMatrix::rand(10, 4);
         let expected: Vec<(Vec<usize>, Vec<usize>)> = vec![

src/model_selection/mod.rs

@@ -41,7 +41,7 @@
 //!           0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1.,
 //! ];
 //!
-//! let (x_train, x_test, y_train, y_test) = train_test_split(&x, &y, 0.2, true);
+//! let (x_train, x_test, y_train, y_test) = train_test_split(&x, &y, 0.2, true, None);
 //!
 //! println!("X train: {:?}, y train: {}, X test: {:?}, y test: {}",
 //!             x_train.shape(), y_train.len(), x_test.shape(), y_test.len());
@@ -107,8 +107,8 @@ use crate::error::Failed;
 use crate::linalg::BaseVector;
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
+use crate::rand::get_rng_impl;
 use rand::seq::SliceRandom;
-use rand::thread_rng;
 
 pub(crate) mod kfold;
 
@@ -130,11 +130,13 @@ pub trait BaseKFold {
 /// * `y` - target values, should be of size _N_
 /// * `test_size`, (0, 1] - the proportion of the dataset to include in the test split.
 /// * `shuffle`, - whether or not to shuffle the data before splitting
+/// * `seed` - Controls the shuffling applied to the data before applying the split. Pass an int for reproducible output across multiple function calls
 pub fn train_test_split<T: RealNumber, M: Matrix<T>>(
     x: &M,
     y: &M::RowVector,
     test_size: f32,
     shuffle: bool,
+    seed: Option<u64>,
 ) -> (M, M, M::RowVector, M::RowVector) {
     if x.shape().0 != y.len() {
         panic!(
@@ -143,6 +145,7 @@ pub fn train_test_split<T: RealNumber, M: Matrix<T>>(
             y.len()
         );
     }
+    let mut rng = get_rng_impl(seed);
 
     if test_size <= 0. || test_size > 1.0 {
         panic!("test_size should be between 0 and 1");
@@ -159,7 +162,7 @@ pub fn train_test_split<T: RealNumber, M: Matrix<T>>(
     let mut indices: Vec<usize> = (0..n).collect();
 
     if shuffle {
-        indices.shuffle(&mut thread_rng());
+        indices.shuffle(&mut rng);
     }
 
     let x_train = x.take(&indices[n_test..n], 0);
@@ -292,7 +295,7 @@ mod tests {
         let x: DenseMatrix<f64> = DenseMatrix::rand(n, 3);
         let y = vec![0f64; n];
 
-        let (x_train, x_test, y_train, y_test) = train_test_split(&x, &y, 0.2, true);
+        let (x_train, x_test, y_train, y_test) = train_test_split(&x, &y, 0.2, true, None);
 
         assert!(
             x_train.shape().0 > (n as f64 * 0.65) as usize

src/rand.rs

@@ -0,0 +1,21 @@
+use ::rand::SeedableRng;
+#[cfg(not(feature = "std"))]
+use rand::rngs::SmallRng as RngImpl;
+#[cfg(feature = "std")]
+use rand::rngs::StdRng as RngImpl;
+
+pub(crate) fn get_rng_impl(seed: Option<u64>) -> RngImpl {
+    match seed {
+        Some(seed) => RngImpl::seed_from_u64(seed),
+        None => {
+            cfg_if::cfg_if! {
+                if #[cfg(feature = "std")] {
+                    use rand::RngCore;
+                    RngImpl::seed_from_u64(rand::thread_rng().next_u64())
+                } else {
+                    panic!("seed number needed for non-std build");
+                }
+            }
+        }
+    }
+}

src/svm/svc.rs

@@ -84,6 +84,7 @@ use crate::error::Failed;
 use crate::linalg::BaseVector;
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
+use crate::rand::get_rng_impl;
 use crate::svm::{Kernel, Kernels, LinearKernel};
 
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -100,6 +101,8 @@ pub struct SVCParameters<T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>
     pub kernel: K,
     /// Unused parameter.
     m: PhantomData<M>,
+    /// Controls the pseudo random number generation for shuffling the data for probability estimates
+    seed: Option<u64>,
 }
 
 /// SVC grid search parameters
@@ -279,8 +282,15 @@ impl<T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>> SVCParameters<T, M
             tol: self.tol,
             kernel,
             m: PhantomData,
+            seed: self.seed,
         }
     }
+
+    /// Seed for the pseudo random number generator.
+    pub fn with_seed(mut self, seed: Option<u64>) -> Self {
+        self.seed = seed;
+        self
+    }
 }
 
 impl<T: RealNumber, M: Matrix<T>> Default for SVCParameters<T, M, LinearKernel> {
@@ -291,6 +301,7 @@ impl<T: RealNumber, M: Matrix<T>> Default for SVCParameters<T, M, LinearKernel>
             tol: T::from_f64(1e-3).unwrap(),
             kernel: Kernels::linear(),
             m: PhantomData,
+            seed: None,
         }
     }
 }
@@ -511,7 +522,7 @@ impl<'a, T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>> Optimizer<'a,
         let good_enough = T::from_i32(1000).unwrap();
 
         for _ in 0..self.parameters.epoch {
-            for i in Self::permutate(n) {
+            for i in self.permutate(n) {
                 self.process(i, self.x.get_row(i), self.y.get(i), &mut cache);
                 loop {
                     self.reprocess(tol, &mut cache);
@@ -544,7 +555,7 @@ impl<'a, T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>> Optimizer<'a,
         let mut cp = 0;
         let mut cn = 0;
 
-        for i in Self::permutate(n) {
+        for i in self.permutate(n) {
             if self.y.get(i) == T::one() && cp < few {
                 if self.process(i, self.x.get_row(i), self.y.get(i), cache) {
                     cp += 1;
@@ -669,8 +680,8 @@ impl<'a, T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>> Optimizer<'a,
         self.recalculate_minmax_grad = true;
     }
 
-    fn permutate(n: usize) -> Vec<usize> {
-        let mut rng = rand::thread_rng();
+    fn permutate(&self, n: usize) -> Vec<usize> {
+        let mut rng = get_rng_impl(self.parameters.seed);
         let mut range: Vec<usize> = (0..n).collect();
         range.shuffle(&mut rng);
         range
@@ -893,7 +904,8 @@ mod tests {
             &y,
             SVCParameters::default()
                 .with_c(200.0)
-                .with_kernel(Kernels::linear()),
+                .with_kernel(Kernels::linear())
+                .with_seed(Some(100)),
         )
         .and_then(|lr| lr.predict(&x))
         .unwrap();

src/tree/decision_tree_classifier.rs

@@ -77,6 +77,7 @@ use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
+use crate::rand::get_rng_impl;
 
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone)]
@@ -90,6 +91,8 @@ pub struct DecisionTreeClassifierParameters {
     pub min_samples_leaf: usize,
     /// The minimum number of samples required to split an internal node.
     pub min_samples_split: usize,
+    /// Controls the randomness of the estimator
+    pub seed: Option<u64>,
 }
 
 /// Decision Tree
@@ -197,6 +200,7 @@ impl Default for DecisionTreeClassifierParameters {
             max_depth: None,
             min_samples_leaf: 1,
             min_samples_split: 2,
+            seed: None,
         }
     }
 }
@@ -467,14 +471,7 @@ impl<T: RealNumber> DecisionTreeClassifier<T> {
     ) -> Result<DecisionTreeClassifier<T>, Failed> {
         let (x_nrows, num_attributes) = x.shape();
         let samples = vec![1; x_nrows];
-        DecisionTreeClassifier::fit_weak_learner(
-            x,
-            y,
-            samples,
-            num_attributes,
-            parameters,
-            &mut rand::thread_rng(),
-        )
+        DecisionTreeClassifier::fit_weak_learner(x, y, samples, num_attributes, parameters)
     }
 
     pub(crate) fn fit_weak_learner<M: Matrix<T>>(
@@ -483,7 +480,6 @@ impl<T: RealNumber> DecisionTreeClassifier<T> {
         samples: Vec<usize>,
         mtry: usize,
         parameters: DecisionTreeClassifierParameters,
-        rng: &mut impl Rng,
     ) -> Result<DecisionTreeClassifier<T>, Failed> {
         let y_m = M::from_row_vector(y.clone());
         let (_, y_ncols) = y_m.shape();
@@ -497,6 +493,7 @@ impl<T: RealNumber> DecisionTreeClassifier<T> {
             )));
         }
 
+        let mut rng = get_rng_impl(parameters.seed);
         let mut yi: Vec<usize> = vec![0; y_ncols];
 
         for (i, yi_i) in yi.iter_mut().enumerate().take(y_ncols) {
@@ -531,13 +528,13 @@ impl<T: RealNumber> DecisionTreeClassifier<T> {
 
         let mut visitor_queue: LinkedList<NodeVisitor<'_, T, M>> = LinkedList::new();
 
-        if tree.find_best_cutoff(&mut visitor, mtry, rng) {
+        if tree.find_best_cutoff(&mut visitor, mtry, &mut rng) {
             visitor_queue.push_back(visitor);
         }
 
         while tree.depth < tree.parameters.max_depth.unwrap_or(std::u16::MAX) {
             match visitor_queue.pop_front() {
-                Some(node) => tree.split(node, mtry, &mut visitor_queue, rng),
+                Some(node) => tree.split(node, mtry, &mut visitor_queue, &mut rng),
                 None => break,
             };
         }
@@ -874,7 +871,8 @@ mod tests {
                     criterion: SplitCriterion::Entropy,
                     max_depth: Some(3),
                     min_samples_leaf: 1,
-                    min_samples_split: 2
+                    min_samples_split: 2,
+                    seed: None
                 }
             )
             .unwrap()

src/tree/decision_tree_regressor.rs

@@ -72,6 +72,7 @@ use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
+use crate::rand::get_rng_impl;
 
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone)]
@@ -83,6 +84,8 @@ pub struct DecisionTreeRegressorParameters {
     pub min_samples_leaf: usize,
     /// The minimum number of samples required to split an internal node.
     pub min_samples_split: usize,
+    /// Controls the randomness of the estimator
+    pub seed: Option<u64>,
 }
 
 /// Regression Tree
@@ -130,6 +133,7 @@ impl Default for DecisionTreeRegressorParameters {
             max_depth: None,
             min_samples_leaf: 1,
             min_samples_split: 2,
+            seed: None,
         }
     }
 }
@@ -357,14 +361,7 @@ impl<T: RealNumber> DecisionTreeRegressor<T> {
     ) -> Result<DecisionTreeRegressor<T>, Failed> {
         let (x_nrows, num_attributes) = x.shape();
         let samples = vec![1; x_nrows];
-        DecisionTreeRegressor::fit_weak_learner(
-            x,
-            y,
-            samples,
-            num_attributes,
-            parameters,
-            &mut rand::thread_rng(),
-        )
+        DecisionTreeRegressor::fit_weak_learner(x, y, samples, num_attributes, parameters)
     }
 
     pub(crate) fn fit_weak_learner<M: Matrix<T>>(
@@ -373,7 +370,6 @@ impl<T: RealNumber> DecisionTreeRegressor<T> {
         samples: Vec<usize>,
         mtry: usize,
         parameters: DecisionTreeRegressorParameters,
-        rng: &mut impl Rng,
     ) -> Result<DecisionTreeRegressor<T>, Failed> {
         let y_m = M::from_row_vector(y.clone());
 
@@ -381,6 +377,7 @@ impl<T: RealNumber> DecisionTreeRegressor<T> {
         let (_, num_attributes) = x.shape();
 
         let mut nodes: Vec<Node<T>> = Vec::new();
+        let mut rng = get_rng_impl(parameters.seed);
 
         let mut n = 0;
         let mut sum = T::zero();
@@ -407,13 +404,13 @@ impl<T: RealNumber> DecisionTreeRegressor<T> {
 
         let mut visitor_queue: LinkedList<NodeVisitor<'_, T, M>> = LinkedList::new();
 
-        if tree.find_best_cutoff(&mut visitor, mtry, rng) {
+        if tree.find_best_cutoff(&mut visitor, mtry, &mut rng) {
             visitor_queue.push_back(visitor);
         }
 
         while tree.depth < tree.parameters.max_depth.unwrap_or(std::u16::MAX) {
             match visitor_queue.pop_front() {
-                Some(node) => tree.split(node, mtry, &mut visitor_queue, rng),
+                Some(node) => tree.split(node, mtry, &mut visitor_queue, &mut rng),
                 None => break,
             };
         }
@@ -699,6 +696,7 @@ mod tests {
                 max_depth: Option::None,
                 min_samples_leaf: 2,
                 min_samples_split: 6,
+                seed: None,
             },
         )
         .and_then(|t| t.predict(&x))
@@ -719,6 +717,7 @@ mod tests {
                 max_depth: Option::None,
                 min_samples_leaf: 1,
                 min_samples_split: 3,
+                seed: None,
             },
         )
         .and_then(|t| t.predict(&x))