feat: Add numpy constants (#428)

* add numpy constants

* feat: add unittests

* add newaxis

* add test for newaxis transformation

* refactor

python/src/CMakeLists.txt

@@ -12,6 +12,7 @@ pybind11_add_module(
   ${CMAKE_CURRENT_SOURCE_DIR}/transforms.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/random.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/linalg.cpp
+  ${CMAKE_CURRENT_SOURCE_DIR}/constants.cpp
 )
 
 if (NOT MLX_PYTHON_BINDINGS_OUTPUT_DIRECTORY)

python/src/constants.cpp

@@ -0,0 +1,24 @@
+// init_constants.cpp
+
+#include <pybind11/pybind11.h>
+#include <limits>
+
+namespace py = pybind11;
+
+void init_constants(py::module_& m) {
+  m.attr("Inf") = std::numeric_limits<double>::infinity();
+  m.attr("Infinity") = std::numeric_limits<double>::infinity();
+  m.attr("NAN") = NAN;
+  m.attr("NINF") = -std::numeric_limits<double>::infinity();
+  m.attr("NZERO") = -0.0;
+  m.attr("NaN") = NAN;
+  m.attr("PINF") = std::numeric_limits<double>::infinity();
+  m.attr("PZERO") = 0.0;
+  m.attr("e") = 2.71828182845904523536028747135266249775724709369995;
+  m.attr("euler_gamma") = 0.5772156649015328606065120900824024310421;
+  m.attr("inf") = std::numeric_limits<double>::infinity();
+  m.attr("infty") = std::numeric_limits<double>::infinity();
+  m.attr("nan") = NAN;
+  m.attr("newaxis") = pybind11::none();
+  m.attr("pi") = 3.1415926535897932384626433;
+}

python/src/mlx.cpp

@@ -16,6 +16,7 @@ void init_transforms(py::module_&);
 void init_random(py::module_&);
 void init_fft(py::module_&);
 void init_linalg(py::module_&);
+void init_constants(py::module_&);
 
 PYBIND11_MODULE(core, m) {
   m.doc() = "mlx: A framework for machine learning on Apple silicon.";
@@ -31,5 +32,6 @@ PYBIND11_MODULE(core, m) {
   init_random(m);
   init_fft(m);
   init_linalg(m);
+  init_constants(m);
   m.attr("__version__") = TOSTRING(_VERSION_);
 }

python/tests/test_constants.py

@@ -0,0 +1,59 @@
+# Copyright © 2023 Apple Inc.
+
+import unittest
+
+import mlx.core as mx
+import mlx_tests
+import numpy as np
+
+
+class TestConstants(mlx_tests.MLXTestCase):
+    def test_constants_values(self):
+        # Check if mlx constants match expected values
+        self.assertAlmostEqual(mx.Inf, float("inf"))
+        self.assertAlmostEqual(mx.Infinity, float("inf"))
+        self.assertTrue(np.isnan(mx.NAN))
+        self.assertAlmostEqual(mx.NINF, float("-inf"))
+        self.assertEqual(mx.NZERO, -0.0)
+        self.assertTrue(np.isnan(mx.NaN))
+        self.assertAlmostEqual(mx.PINF, float("inf"))
+        self.assertEqual(mx.PZERO, 0.0)
+        self.assertAlmostEqual(
+            mx.e, 2.71828182845904523536028747135266249775724709369995
+        )
+        self.assertAlmostEqual(
+            mx.euler_gamma, 0.5772156649015328606065120900824024310421
+        )
+        self.assertAlmostEqual(mx.inf, float("inf"))
+        self.assertAlmostEqual(mx.infty, float("inf"))
+        self.assertTrue(np.isnan(mx.nan))
+        self.assertIsNone(mx.newaxis)
+        self.assertAlmostEqual(mx.pi, 3.1415926535897932384626433)
+
+    def test_constants_availability(self):
+        # Check if mlx constants are available
+        self.assertTrue(hasattr(mx, "Inf"))
+        self.assertTrue(hasattr(mx, "Infinity"))
+        self.assertTrue(hasattr(mx, "NAN"))
+        self.assertTrue(hasattr(mx, "NINF"))
+        self.assertTrue(hasattr(mx, "NaN"))
+        self.assertTrue(hasattr(mx, "PINF"))
+        self.assertTrue(hasattr(mx, "NZERO"))
+        self.assertTrue(hasattr(mx, "PZERO"))
+        self.assertTrue(hasattr(mx, "e"))
+        self.assertTrue(hasattr(mx, "euler_gamma"))
+        self.assertTrue(hasattr(mx, "inf"))
+        self.assertTrue(hasattr(mx, "infty"))
+        self.assertTrue(hasattr(mx, "nan"))
+        self.assertTrue(hasattr(mx, "newaxis"))
+        self.assertTrue(hasattr(mx, "pi"))
+
+    def test_newaxis_for_reshaping_arrays(self):
+        arr_1d = mx.array([1, 2, 3, 4, 5])
+        arr_2d_column = arr_1d[:, mx.newaxis]
+        expected_result = mx.array([[1], [2], [3], [4], [5]])
+        self.assertTrue(mx.array_equal(arr_2d_column, expected_result))
+
+
+if __name__ == "__main__":
+    unittest.main()