feat: adds LASSO

src/linalg/high_order.rs

@@ -0,0 +1,28 @@
+//! In this module you will find composite of matrix operations that are used elsewhere
+//! for improved efficiency.
+
+use crate::linalg::BaseMatrix;
+use crate::math::num::RealNumber;
+
+/// High order matrix operations.
+pub trait HighOrderOperations<T: RealNumber>: BaseMatrix<T> {
+    /// Y = AB
+    /// ```
+    /// use smartcore::linalg::naive::dense_matrix::*;
+    /// use smartcore::linalg::high_order::HighOrderOperations;
+    ///
+    /// let a = DenseMatrix::from_2d_array(&[&[1., 2.], &[3., 4.], &[5., 6.]]);
+    /// let b = DenseMatrix::from_2d_array(&[&[5., 6.], &[7., 8.], &[9., 10.]]);
+    /// let expected = DenseMatrix::from_2d_array(&[&[71., 80.], &[92., 104.]]);
+    ///
+    /// assert_eq!(a.ab(true, &b, false), expected);
+    /// ```
+    fn ab(&self, a_transpose: bool, b: &Self, b_transpose: bool) -> Self {
+        match (a_transpose, b_transpose) {
+            (true, true) => self.transpose().matmul(&b.transpose()),
+            (false, true) => self.matmul(&b.transpose()),
+            (true, false) => self.transpose().matmul(b),
+            (false, false) => self.matmul(b),
+        }
+    }
+}