BUG: object array np.conjugate, ndarray.conjugate inconsistent

fixes numpygh-4730

Author: ewmoore

numpy/core/src/multiarray/calculation.c

@@ -1182,7 +1182,7 @@ PyArray_Clip(PyArrayObject *self, PyObject *min, PyObject *max, PyArrayObject *o
 NPY_NO_EXPORT PyObject *
 PyArray_Conjugate(PyArrayObject *self, PyArrayObject *out)
 {
-    if (PyArray_ISCOMPLEX(self)) {
+    if (PyArray_ISCOMPLEX(self) || PyArray_ISOBJECT(self)) {
         if (out == NULL) {
             return PyArray_GenericUnaryFunction(self,
                                                 n_ops.conjugate);

numpy/core/tests/test_multiarray.py

@@ -1675,6 +1675,43 @@ def test_ravel(self):
         assert_equal(a.ravel(order='K'), [2, 3, 0, 1])
         assert_(a.ravel(order='K').flags.owndata)
 
+    def test_conjugate(self):
+        a = np.array([1-1j, 1+1j, 23+23.0j])
+        ac = a.conj()
+        assert_equal(a.real, ac.real)
+        assert_equal(a.imag, -ac.imag)
+        assert_equal(ac, a.conjugate())
+        assert_equal(ac, np.conjugate(a))
+
+        a = np.array([1-1j, 1+1j, 23+23.0j], 'F')
+        ac = a.conj()
+        assert_equal(a.real, ac.real)
+        assert_equal(a.imag, -ac.imag)
+        assert_equal(ac, a.conjugate())
+        assert_equal(ac, np.conjugate(a))
+
+        a = np.array([1, 2, 3])
+        ac = a.conj()
+        assert_equal(a, ac)
+        assert_equal(ac, a.conjugate())
+        assert_equal(ac, np.conjugate(a))
+
+        a = np.array([1.0, 2.0, 3.0])
+        ac = a.conj()
+        assert_equal(a, ac)
+        assert_equal(ac, a.conjugate())
+        assert_equal(ac, np.conjugate(a))
+
+        a = np.array([1-1j, 1+1j, 1, 2.0], object)
+        ac = a.conj()
+        assert_equal(ac, [k.conjugate() for k in a])
+        assert_equal(ac, a.conjugate())
+        assert_equal(ac, np.conjugate(a))
+
+        a = np.array([1-1j, 1, 2.0, 'f'], object)
+        assert_raises(AttributeError, lambda: a.conj())
+        assert_raises(AttributeError, lambda: a.conjugate()) 
+
 
 class TestBinop(object):
     def test_ufunc_override_rop_precedence(self):