deviation: fix definition of sq_l2_dist

Author: munckymagik

src/deviation.rs

@@ -61,7 +61,8 @@ where
 
         Zip::from(self).and(other).apply(|self_i, other_i| {
             let (a, b) = (self_i.clone(), other_i.clone());
-            r += (a - b).abs();
+            let abs_diff = (a - b).abs();
+            r += abs_diff.clone() * abs_diff;
         });
 
         r
@@ -79,6 +80,7 @@ where
 mod tests {
     use super::*;
     use ndarray::array;
+    use num_traits::Pow;
 
     #[test]
     fn test_count_eq() {
@@ -111,12 +113,12 @@ mod tests {
         let a = array![1., 2., 3., 4., 5., 6., 7.];
         let b = array![1., 3., 3., 4., 6., 7., 8.];
 
-        assert_eq!(a.sq_l2_dist(&b), (&a - &b).mapv(f64::abs).sum());
+        assert_eq!(a.sq_l2_dist(&b), (&a - &b).mapv(f64::abs).mapv(|n| n.pow(2)).sum());
 
         let a = array![[1, 2], [3, 4], [5, 6]];
         let b = array![[1, 3], [3, 4], [6, 7]];
 
-        assert_eq!(a.sq_l2_dist(&b), (&a - &b).mapv(i32::abs).sum());
+        assert_eq!(a.sq_l2_dist(&b), (&a - &b).mapv(i32::abs).mapv(|n| n.pow(2)).sum());
     }
 
     #[test]