add performance tests script, only 1 test function right now

test_programs/performance_tests.py

@@ -0,0 +1,48 @@
+#! /usr/bin/python3.6
+
+import numpy as np
+
+from time import time
+
+def test_find_indices_in_other_array():
+    # How many elements should be there
+    n1 = 1000000
+    # How many different numbers there can be
+    n2 = 2000
+
+    # Create random numbers [0, n2]
+    a = np.random.randint(0, n2, (n1, ))
+    # Create random numbers, for what we want to search the index
+    # Should also contain only unique values as possible! (but is not a must!)
+    b = np.random.permutation(np.arange(0, n2))[:np.random.randint(n2//10, n2+1)]
+
+    # 1st approach
+    start_1 = time()
+    idx1 = np.where(np.any(a.reshape((-1, 1))==b, axis=1))[0]
+    diff_1 = time()-start_1
+
+    # 2nd approach
+    start_2 = time()
+    idx2 = np.flatnonzero(np.isin(a,b))
+    diff_2 = time()-start_2
+
+    # 3rd approach
+    start_3 = time()
+    b2 = np.sort(b)
+    sidx = np.searchsorted(b2,a)
+    sidx[sidx==len(b2)] = len(b2)-1
+    idx3 = np.flatnonzero(b2[sidx]==a)
+    diff_3 = time()-start_3
+
+    print("idx1: {}".format(idx1))
+    print("Taken time for approach 1: diff_1: {:1.3f}s".format(diff_1))
+
+    print("idx2: {}".format(idx2))
+    print("Taken time for approach 2: diff_2: {:1.3f}s".format(diff_2))
+
+    print("idx3: {}".format(idx3))
+    print("Taken time for approach 3: diff_3: {:1.3f}s".format(diff_3))
+
+
+if __name__ == "__main__":
+    test_find_indices_in_other_array()