Covariance and Correlation test functions added

Author: Madhav2310

integration_tests/test_statistics.py

@@ -1,5 +1,5 @@
 from statistics import (mean, fmean, geometric_mean, harmonic_mean,
-                        variance, stdev)
+                        variance, stdev, covariance, correlation)
 from ltypes import i32, f64, i64
 
 eps: f64
@@ -66,6 +66,46 @@ def test_variance():
     k = variance(b)
     assert abs(k - 0.40924) < eps
 
+def test_covariance():
+    a: list[i32]
+    a = [1, 2, 3, 4, 5, 6, 7, 8, 9]
+    b: list[i32]
+    b = [1, 2, 3, 1, 2, 3, 1, 2, 3]
+    j: f64
+    j = covariance(a,b)
+    assert abs(j - 0.75) < eps
+
+    c: list[f64]
+    c = [2.74, 1.23, 2.63, 2.22, 3.0, 1.98]
+    d: list[f64]
+    d = [9.4, 1.23, 2.63, 22.4, 1.9, 13.98]
+    k: f64
+    k = covariance(c,d)
+    assert abs(k + 0.24955999999999934) < eps
+
+def test_correlation():
+    a: list[i32]
+    a = [11, 2, 7, 4, 15, 6, 10, 8, 9, 1, 11, 5, 13, 6, 15]
+    b: list[i32]
+    b = [2, 5, 17, 6, 10, 8, 13, 4, 6, 9, 11, 2, 5, 4, 7]
+
+    j: f64
+    j = correlation(a,b)
+    assert abs(j - 0.11521487988958108) < eps
+
+    c: list[i32]
+    c = [1, 2, 3, 4, 5, 6, 7, 8, 9]
+    d: list[i32]
+    d = [9, 8, 7, 6, 5, 4, 3, 2, 1]
+
+    k: f64
+    k = correlation(c,c)
+    assert k == 1.0
+
+    l: f64
+    l = correlation(c,d)
+    assert l == -1.0
+
 
 def test_stdev():
     a: list[i32]
@@ -88,5 +128,7 @@ def check():
     test_fmean()
     test_variance()
     test_stdev()
+    test_covariance()
+    test_correlation()
 
 check()