feat: adds new distance measures + LU decomposition

src/math/distance/hamming.rs

@@ -0,0 +1,45 @@
+use serde::{Serialize, Deserialize};
+
+use crate::math::num::FloatExt;
+
+use super::Distance;
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Hamming {
+}
+
+impl<T: PartialEq, F: FloatExt> Distance<Vec<T>, F> for Hamming {
+
+    fn distance(&self, x: &Vec<T>, y: &Vec<T>) -> F {    
+        if x.len() != y.len() {
+            panic!("Input vector sizes are different");
+        }
+    
+        let mut dist = 0;
+        for i in 0..x.len() {
+            if x[i] != y[i]{
+                dist += 1;
+            }
+        }        
+    
+        F::from_i64(dist).unwrap() / F::from_usize(x.len()).unwrap()
+    } 
+
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;    
+
+    #[test]
+    fn minkowski_distance() {
+        let a = vec![1, 0, 0, 1, 0, 0, 1];
+        let b = vec![1, 1, 0, 0, 1, 0, 1];             
+        
+        let h: f64 = Hamming{}.distance(&a, &b);        
+        
+        assert!((h - 0.42857142).abs() < 1e-8);
+    }  
+    
+}