[OpenVINO backend] Support arctan2, pass the NumpyDtypeTest::arctan2 test (keras-team#20928)

* pass NumpyDtypeTest::arctan2 and add some test cases in NumpyTwoInputOpsCorrectnessTest::arctan2

* newly add NumpyDtypeTest::test_arctan2

Author: AsVoider

keras/src/backend/openvino/excluded_concrete_tests.txt

@@ -7,7 +7,6 @@ NumpyDtypeTest::test_add_
 NumpyDtypeTest::test_all
 NumpyDtypeTest::test_any
 NumpyDtypeTest::test_append_
-NumpyDtypeTest::test_arctan2_
 NumpyDtypeTest::test_argmax
 NumpyDtypeTest::test_argmin
 NumpyDtypeTest::test_argpartition

keras/src/backend/openvino/numpy.py

@@ -272,15 +272,13 @@ def arctan(x):
 def arctan2(x1, x2):
     x1 = get_ov_output(x1)
     x2 = get_ov_output(x2)
-    x1_type = x1.get_element_type()
-    x2_type = x2.get_element_type()
 
-    if x1_type.is_integral():
-        ov_type = OPENVINO_DTYPES[config.floatx()]
-        x1 = ov_opset.convert(x1, ov_type)
-    if x2_type.is_integral():
-        ov_type = OPENVINO_DTYPES[config.floatx()]
-        x2 = ov_opset.convert(x2, ov_type)
+    x1_type = ov_to_keras_type(x1.get_element_type())
+    x2_type = ov_to_keras_type(x2.get_element_type())
+    result_type = dtypes.result_type(x1_type, x2_type, float)
+    result_type = OPENVINO_DTYPES[result_type]
+    x1 = ov_opset.convert(x1, result_type)
+    x2 = ov_opset.convert(x2, result_type)
 
     x = ov_opset.divide(x1, x2)
     y = ov_opset.atan(x)

keras/src/ops/numpy_test.py

@@ -2449,6 +2449,18 @@ def test_arctan2(self):
 
         self.assertAllClose(knp.Arctan2()(x, y), np.arctan2(x, y))
 
+        a = np.array([0.0, 0.0, 0.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0])
+        b = np.array([0.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 0.0, 0.0])
+
+        self.assertAllClose(knp.arctan2(a, b), np.arctan2(a, b))
+        self.assertAllClose(knp.Arctan2()(a, b), np.arctan2(a, b))
+
+        m = np.array([[3, 4], [7, 8]], dtype=np.int8)
+        n = np.array([[1, 2], [3, 4]], dtype=float)
+
+        self.assertAllClose(knp.arctan2(m, n), np.arctan2(m, n))
+        self.assertAllClose(knp.Arctan2()(m, n), np.arctan2(m, n))
+
     def test_bitwise_and(self):
         x = np.array([2, 5, 255])
         y = np.array([3, 14, 16])