Add np.asfarray impl

docs/source/reference/numpysupported.rst

@@ -338,6 +338,7 @@ The following top-level functions are supported:
 * :func:`numpy.array` (only the 2 first arguments)
 * :func:`numpy.array_equal`
 * :func:`numpy.asarray` (only the 2 first arguments)
+* :func:`numpy.asfarray` 
 * :func:`numpy.asfortranarray` (only the first argument)
 * :func:`numpy.atleast_1d`
 * :func:`numpy.atleast_2d`

numba/np/arraymath.py

@@ -4070,6 +4070,19 @@ def impl(a, dtype=None):
     return impl
 
 
+@overload(np.asfarray)
+def np_asfarray(a, dtype=np.float64):
+    dtype = as_dtype(dtype)
+    if not np.issubdtype(dtype, np.inexact):
+        dx = types.float64
+    else:
+        dx = dtype
+
+    def impl(a, dtype=np.float64):
+        return np.asarray(a, dx)
+    return impl
+
+
 @overload(np.extract)
 def np_extract(condition, arr):
 

numba/tests/test_np_functions.py

@@ -245,6 +245,10 @@ def asarray_kws(a, dtype):
     return np.asarray(a, dtype=dtype)
 
 
+def asfarray(a, dtype=np.float64):
+    return np.asfarray(a, dtype=dtype)
+
+
 def extract(condition, arr):
     return np.extract(condition, arr)
 
@@ -3208,6 +3212,28 @@ def make_unicode_list():
         test_reject(make_nested_list_with_dict())
         test_reject(make_unicode_list())
 
+    def test_asfarray(self):
+        def inputs():
+            yield np.array([1, 2, 3]), None
+            yield np.array([2, 3], dtype=np.float32), np.float32
+            yield np.array([2, 3], dtype=np.int8), np.int8
+            yield np.array([2, 3], dtype=np.int8), np.complex64
+            yield np.array([2, 3], dtype=np.int8), np.complex128
+
+        pyfunc = asfarray
+        cfunc = jit(nopython=True)(pyfunc)
+
+        for arr, dt in inputs():
+            if dt is None:
+                expected = pyfunc(arr)
+                got = cfunc(arr)
+            else:
+                expected = pyfunc(arr, dtype=dt)
+                got = cfunc(arr, dtype=dt)
+
+            self.assertPreciseEqual(expected, got)
+            self.assertTrue(np.issubdtype(got.dtype, np.inexact), got.dtype)
+
     def test_repeat(self):
         # np.repeat(a, repeats)
         np_pyfunc = np_repeat