feat: adds new distance measures + LU decomposition

src/math/distance/manhattan.rs

@@ -0,0 +1,43 @@
+use serde::{Serialize, Deserialize};
+
+use crate::math::num::FloatExt;
+
+use super::Distance;
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Manhattan {
+}
+
+impl<T: FloatExt> Distance<Vec<T>, T> for Manhattan {
+
+    fn distance(&self, x: &Vec<T>, y: &Vec<T>) -> T {    
+        if x.len() != y.len() {
+            panic!("Input vector sizes are different");
+        }
+    
+        let mut dist = T::zero();
+        for i in 0..x.len() {            
+            dist = dist + (x[i] - y[i]).abs();            
+        }        
+    
+        dist
+    } 
+
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;    
+
+    #[test]
+    fn manhattan_distance() {
+        let a = vec![1., 2., 3.];
+        let b = vec![4., 5., 6.];             
+        
+        let l1: f64 = Manhattan{}.distance(&a, &b);             
+
+        assert!((l1 - 9.0).abs() < 1e-8);        
+    } 
+
+}