feat: adds elastic net

Author: Volodymyr Orlov

src/linalg/mod.rs

@@ -271,6 +271,9 @@ pub trait BaseVector<T: RealNumber>: Clone + Debug {
     fn std(&self) -> T {
         self.var().sqrt()
     }
+
+    /// Copies content of `other` vector.
+    fn copy_from(&mut self, other: &Self);
 }
 
 /// Generic matrix type.

src/linalg/naive/dense_matrix.rs

@@ -176,6 +176,20 @@ impl<T: RealNumber> BaseVector<T> for Vec<T> {
         result.dedup();
         result
     }
+
+    fn copy_from(&mut self, other: &Self) {
+        if self.len() != other.len() {
+            panic!(
+                "Can't copy vector of length {} into a vector of length {}.",
+                self.len(),
+                other.len()
+            );
+        }
+
+        for i in 0..self.len() {
+            self[i] = other[i];
+        }
+    }
 }
 
 /// Column-major, dense matrix. See [Simple Dense Matrix](../index.html).

src/linalg/nalgebra_bindings.rs

@@ -181,6 +181,10 @@ impl<T: RealNumber + 'static> BaseVector<T> for MatrixMN<T, U1, Dynamic> {
         result.dedup();
         result
     }
+
+    fn copy_from(&mut self, other: &Self) {
+        Matrix::copy_from(self, other);
+    }
 }
 
 impl<T: RealNumber + Scalar + AddAssign + SubAssign + MulAssign + DivAssign + Sum + 'static>
@@ -575,6 +579,16 @@ mod tests {
     use crate::linear::linear_regression::*;
     use nalgebra::{DMatrix, Matrix2x3, RowDVector};
 
+    #[test]
+    fn vec_copy_from() {
+        let mut v1 = RowDVector::from_vec(vec![1., 2., 3.]);
+        let mut v2 = RowDVector::from_vec(vec![4., 5., 6.]);
+        v1.copy_from(&v2);
+        assert_eq!(v2, v1);
+        v2[0] = 10.0;
+        assert_ne!(v2, v1);
+    }
+
     #[test]
     fn vec_len() {
         let v = RowDVector::from_vec(vec![1., 2., 3.]);

src/linalg/ndarray_bindings.rs

@@ -176,6 +176,10 @@ impl<T: RealNumber + ScalarOperand> BaseVector<T> for ArrayBase<OwnedRepr<T>, Ix
         result.dedup();
         result
     }
+
+    fn copy_from(&mut self, other: &Self) {
+        self.assign(&other);
+    }
 }
 
 impl<T: RealNumber + ScalarOperand + AddAssign + SubAssign + MulAssign + DivAssign + Sum>
@@ -537,6 +541,16 @@ mod tests {
         assert_eq!(5., BaseVector::get(&result, 1));
     }
 
+    #[test]
+    fn vec_copy_from() {
+        let mut v1 = arr1(&[1., 2., 3.]);
+        let mut v2 = arr1(&[4., 5., 6.]);
+        v1.copy_from(&v2);
+        assert_eq!(v1, v2);
+        v2[0] = 10.0;
+        assert_ne!(v1, v2);
+    }
+
     #[test]
     fn vec_len() {
         let v = arr1(&[1., 2., 3.]);