Add a new method for standard DotProduct for users seeking non-normalized score (#876)

Co-authored-by: Shashank Paliwal <spaliwal@spaliwal-mn1.linkedin.biz>

Author: shashankiiit

feathr-impl/src/main/java/com/linkedin/feathr/common/util/MvelContextUDFs.java

@@ -364,6 +364,31 @@ public static Float cosineSimilarity(Object obj1, Object obj2) {
     }
   }
 
+  /**
+   * Returns a standard dotProduct of two vector objects.
+   * Use {@link MvelContextUDFs#cosineSimilarity(Object, Object)} for normalized dot-product.
+   */
+  @ExportToMvel
+  public static Double dotProduct(Object obj1, Object obj2) {
+    if (obj1 == null || obj2 == null) {
+      return null;
+    }
+    Map<String, Float> mapA = CoercionUtils.coerceToVector(obj1);
+    Map<String, Float> mapB = CoercionUtils.coerceToVector(obj2);
+    double dotProduct = 0;
+
+    for (Map.Entry<String, Float> entry : mapA.entrySet()) {
+      String k = entry.getKey();
+      float valA = entry.getValue();
+      Float valB = mapB.get(k);
+      if (valB != null) {
+        dotProduct += ((double) valA * valB);
+      }
+    }
+
+    return dotProduct;
+  }
+
   /**
    * convert input to lower case string
    * @param input input string

feathr-impl/src/test/java/com/linkedin/feathr/offline/TestMvelContext.java

@@ -30,4 +30,24 @@ public void testCosineSimilarity() {
     categoricalOutput2.clear();
     assertEquals(cosineSimilarity(categoricalOutput1, categoricalOutput2), 0.0F);
   }
+
+  @Test
+  public void testDotProduct() {
+    // Test basic dot product calculation
+    Map<String, Float> categoricalOutput1 = new HashMap<>();
+    categoricalOutput1.put("A", 1F);
+    categoricalOutput1.put("B", 1F);
+
+    Map<String, Float> categoricalOutput2 = new HashMap<>();
+    categoricalOutput2.put("B", 1F);
+    categoricalOutput2.put("C", 1F);
+
+    assertEquals(dotProduct(categoricalOutput1, categoricalOutput2), 1.0D);
+
+    // Test dot product of zero vectors
+    categoricalOutput1.clear();
+    assertEquals(dotProduct(categoricalOutput1, categoricalOutput2), 0.0D);
+    categoricalOutput2.clear();
+    assertEquals(dotProduct(categoricalOutput1, categoricalOutput2), 0.0D);
+  }
 }