feat: + cross_validate, trait Predictor, refactoring

src/math/distance/euclidian.rs

@@ -25,7 +25,7 @@ use crate::math::num::RealNumber;
 use super::Distance;
 
 /// Euclidean distance is a measure of the true straight line distance between two points in Euclidean n-space.
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Euclidian {}
 
 impl Euclidian {

src/math/distance/hamming.rs

@@ -26,7 +26,7 @@ use crate::math::num::RealNumber;
 use super::Distance;
 
 /// While comparing two integer-valued vectors of equal length, Hamming distance is the number of bit positions in which the two bits are different
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Hamming {}
 
 impl<T: PartialEq, F: RealNumber> Distance<Vec<T>, F> for Hamming {

src/math/distance/mahalanobis.rs

@@ -52,7 +52,7 @@ use super::Distance;
 use crate::linalg::Matrix;
 
 /// Mahalanobis distance.
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Mahalanobis<T: RealNumber, M: Matrix<T>> {
     /// covariance matrix of the dataset
     pub sigma: M,

src/math/distance/manhattan.rs

@@ -24,7 +24,7 @@ use crate::math::num::RealNumber;
 use super::Distance;
 
 /// Manhattan distance
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Manhattan {}
 
 impl<T: RealNumber> Distance<Vec<T>, T> for Manhattan {

src/math/distance/minkowski.rs

@@ -28,7 +28,7 @@ use crate::math::num::RealNumber;
 use super::Distance;
 
 /// Defines the Minkowski distance of order `p`
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Minkowski {
     /// order, integer
     pub p: u16,

src/math/distance/mod.rs

@@ -28,7 +28,7 @@ use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
 
 /// Distance metric, a function that calculates distance between two points
-pub trait Distance<T, F: RealNumber> {
+pub trait Distance<T, F: RealNumber>: Clone {
     /// Calculates distance between _a_ and _b_
     fn distance(&self, a: &T, b: &T) -> F;
 }