1 files changed, 20 insertions, 0 deletions
diff --git a/example/ndpiReader.c b/example/ndpiReader.c
index 207056785..32b7399cd 100644
--- a/example/ndpiReader.c
+++ b/example/ndpiReader.c
@@ -5951,6 +5951,25 @@ void memmemUnitTest(void) {
 
 /* *********************************************** */
 
+void mahalanobisUnitTest()
+{
+  /* Example based on: https://supplychenmanagement.com/2019/03/06/calculating-mahalanobis-distance/ */
+
+  const float i_s[3 * 3] = {  0.0482486100061447, -0.00420645518018837, -0.0138921893248235,
+                             -0.00420645518018836, 0.00177288408892603, -0.00649813703331057,
+                             -0.0138921893248235, -0.00649813703331056,  0.066800436339011 }; /* Inverted covar matrix */
+  const float u[3] = { 22.8, 180.0, 9.2 }; /* Means vector */
+  u_int32_t x[3] = { 26, 167, 12 }; /* Point */
+  float md;
+
+  md = ndpi_mahalanobis_distance(x, 3, u, i_s);
+  /* It is a bit tricky to test float equality on different archs -> loose check.
+   * md sholud be 1.3753 */
+  assert(md >= 1.37 && md <= 1.38);
+}
+
+/* *********************************************** */
+
 void filterUnitTest() {
   ndpi_filter* f = ndpi_filter_alloc();
   u_int32_t v, i;
@@ -6440,6 +6459,7 @@ int main(int argc, char **argv) {
     strnstrUnitTest();
     strncasestrUnitTest();
     memmemUnitTest();
+    mahalanobisUnitTest();
 #endif
   }