Use wrappers to complete SciPy and NumPy interface namespaces

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Replaced `fwd_scale` parameter with `norm` in `mkl_fft` [gh-189](https://github.com/IntelPython/mkl_fft/pull/189)
 * Dropped support for `scipy.fftpack` interface [gh-185](https://github.com/IntelPython/mkl_fft/pull/185)
 * Dropped support for `overwrite_x` parameter in `mkl_fft` [gh-185](https://github.com/IntelPython/mkl_fft/pull/185)
+* Added thin wrappers for `fftfreq`, `rfftfreq`, `fftshift`, and `ifftshift` to `scipy_fft` interface [gh-226](https://github.com/IntelPython/mkl_fft/pull/226)
 
 ### Fixed
 * Fixed a bug for N-D FFTs when both `s` and `out` are given [gh-185](https://github.com/IntelPython/mkl_fft/pull/185)

mkl_fft/interfaces/_scipy_fft.py

@@ -36,6 +36,7 @@
 
 import mkl
 import numpy as np
+import scipy
 
 import mkl_fft
 
@@ -61,6 +62,10 @@
     "ihfft2",
     "hfftn",
     "ihfftn",
+    "fftshift",
+    "ifftshift",
+    "fftfreq",
+    "rfftfreq",
     "get_workers",
     "set_workers",
 ]
@@ -650,6 +655,49 @@ def ihfftn(
     return result
 
 
+# define thin wrappers for scipy functions to avoid circular dependencies
+def fftfreq(n, d=1.0, *, xp=None, device=None):
+    """
+    Return the Discrete Fourier Transform sample frequencies.
+
+    For full documentation refer to `scipy.fft.fftfreq`.
+
+    """
+    return scipy.fft.fftfreq(n, d=d, xp=xp, device=device)
+
+
+def rfftfreq(n, d=1.0, *, xp=None, device=None):
+    """
+    Return the Discrete Fourier Transform sample frequencies (for usage with
+    `rfft`, `irfft`).
+
+    For full documentation refer to `scipy.fft.rfftfreq`.
+
+    """
+    return scipy.fft.rfftfreq(n, d=d, xp=xp, device=device)
+
+
+def fftshift(x, axes=None):
+    """
+    Shift the zero-frequency component to the center of the spectrum.
+
+    For full documentation refer to `scipy.fft.fftshift`.
+
+    """
+    return scipy.fft.fftshift(x, axes=axes)
+
+
+def ifftshift(x, axes=None):
+    """
+    The inverse of `fftshift`. Although identical for even-length `x`, the
+    functions differ by one sample for odd-length `x`.
+
+    For full documentation refer to `scipy.fft.ifftshift`.
+
+    """
+    return scipy.fft.ifftshift(x, axes=axes)
+
+
 def get_workers():
     """
     Gets the number of workers used by mkl_fft by default.

mkl_fft/interfaces/scipy_fft.py

@@ -24,22 +24,21 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
-# Added for completing the namespaces
-from scipy.fft import fftfreq, fftshift, ifftshift, rfftfreq
-
 # pylint: disable=no-name-in-module
 from ._scipy_fft import (
     fft,
     fft2,
+    fftfreq,
     fftn,
+    fftshift,
     get_workers,
     hfft,
     hfft2,
     hfftn,
     ifft,
     ifft2,
     ifftn,
+    ifftshift,
     ihfft,
     ihfft2,
     ihfftn,
@@ -48,6 +47,7 @@
     irfftn,
     rfft,
     rfft2,
+    rfftfreq,
     rfftn,
     set_workers,
 )