conditional import scipy_fft

.gitignore

@@ -7,4 +7,5 @@ __pycache__/
 
 mkl_fft/_pydfti.c
 mkl_fft/_pydfti.cpython*.so
+mkl_fft/_pydfti.*-win_amd64.pyd
 mkl_fft/src/mklfft.c

README.md

@@ -93,6 +93,7 @@ To build `mkl_fft` from sources on Linux with Intel® OneMKL:
   - `git clone https://github.com/IntelPython/mkl_fft.git mkl_fft`
   - `cd mkl_fft`
   - `python -m pip install .`
+  - `pip install scipy` (optional: for using `mkl_fft.interface.scipy_fft` module)
   - `cd ..`
   - `python -c "import mkl_fft"`
 
@@ -103,5 +104,6 @@ To build `mkl_fft` from sources on Linux with conda follow these steps:
   - `git clone https://github.com/IntelPython/mkl_fft.git mkl_fft`
   - `cd mkl_fft`
   - `python -m pip install .`
+  - `conda install scipy` (optional: for using `mkl_fft.interface.scipy_fft` module)
   - `cd ..`
   - `python -c "import mkl_fft"`

conda-recipe-cf/meta.yaml

@@ -32,7 +32,7 @@ test:
       - pytest -v --pyargs mkl_fft
     requires:
       - pytest
-      - scipy
+      - scipy >=1.10
     imports:
       - mkl_fft
       - mkl_fft.interfaces

conda-recipe/meta.yaml

@@ -33,7 +33,7 @@ test:
       - pytest -v --pyargs mkl_fft
     requires:
       - pytest
-      - scipy
+      - scipy >=1.10
     imports:
       - mkl_fft
       - mkl_fft.interfaces

mkl_fft/interfaces/__init__.py

@@ -23,4 +23,11 @@
 # 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.
 
-from . import numpy_fft, scipy_fft
+from . import numpy_fft
+
+try:
+    import scipy.fft
+except ImportError:
+    pass
+else:
+    from . import scipy_fft

mkl_fft/tests/test_interfaces.py

@@ -29,12 +29,26 @@
 
 import mkl_fft.interfaces as mfi
 
+try:
+    scipy_fft = mfi.scipy_fft
+except AttributeError:
+    scipy_fft = None
+
+interfaces = []
+ids = []
+if scipy_fft is not None:
+    interfaces.append(scipy_fft)
+    ids.append("scipy")
+interfaces.append(mfi.numpy_fft)
+ids.append("numpy")
+
 
 @pytest.mark.parametrize("norm", [None, "forward", "backward", "ortho"])
 @pytest.mark.parametrize(
     "dtype", [np.float32, np.float64, np.complex64, np.complex128]
 )
 def test_scipy_fft(norm, dtype):
+    pytest.importorskip("scipy", reason="requires scipy")
     x = np.ones(511, dtype=dtype)
     w = mfi.scipy_fft.fft(x, norm=norm, workers=None, plan=None)
     xx = mfi.scipy_fft.ifft(w, norm=norm, workers=None, plan=None)
@@ -57,6 +71,7 @@ def test_numpy_fft(norm, dtype):
 @pytest.mark.parametrize("norm", [None, "forward", "backward", "ortho"])
 @pytest.mark.parametrize("dtype", [np.float32, np.float64])
 def test_scipy_rfft(norm, dtype):
+    pytest.importorskip("scipy", reason="requires scipy")
     x = np.ones(511, dtype=dtype)
     w = mfi.scipy_fft.rfft(x, norm=norm, workers=None, plan=None)
     xx = mfi.scipy_fft.irfft(
@@ -87,6 +102,7 @@ def test_numpy_rfft(norm, dtype):
     "dtype", [np.float32, np.float64, np.complex64, np.complex128]
 )
 def test_scipy_fftn(norm, dtype):
+    pytest.importorskip("scipy", reason="requires scipy")
     x = np.ones((37, 83), dtype=dtype)
     w = mfi.scipy_fft.fftn(x, norm=norm, workers=None, plan=None)
     xx = mfi.scipy_fft.ifftn(w, norm=norm, workers=None, plan=None)
@@ -109,6 +125,7 @@ def test_numpy_fftn(norm, dtype):
 @pytest.mark.parametrize("norm", [None, "forward", "backward", "ortho"])
 @pytest.mark.parametrize("dtype", [np.float32, np.float64])
 def test_scipy_rfftn(norm, dtype):
+    pytest.importorskip("scipy", reason="requires scipy")
     x = np.ones((37, 83), dtype=dtype)
     w = mfi.scipy_fft.rfftn(x, norm=norm, workers=None, plan=None)
     xx = mfi.scipy_fft.irfftn(w, s=x.shape, norm=norm, workers=None, plan=None)
@@ -143,32 +160,30 @@ def _get_blacklisted_dtypes():
 
 @pytest.mark.parametrize("dtype", _get_blacklisted_dtypes())
 def test_scipy_no_support_for(dtype):
+    pytest.importorskip("scipy", reason="requires scipy")
     x = np.ones(16, dtype=dtype)
     assert_raises(NotImplementedError, mfi.scipy_fft.ifft, x)
 
 
 def test_scipy_fft_arg_validate():
+    pytest.importorskip("scipy", reason="requires scipy")
     with pytest.raises(ValueError):
         mfi.scipy_fft.fft([1, 2, 3, 4], norm=b"invalid")
 
     with pytest.raises(NotImplementedError):
         mfi.scipy_fft.fft([1, 2, 3, 4], plan="magic")
 
 
-@pytest.mark.parametrize(
-    "func", [mfi.scipy_fft.rfft2, mfi.numpy_fft.rfft2], ids=["scipy", "numpy"]
-)
-def test_axes(func):
+@pytest.mark.parametrize("interface", interfaces, ids=ids)
+def test_axes(interface):
     x = np.arange(24.0).reshape(2, 3, 4)
-    res = func(x, axes=(1, 2))
+    res = interface.rfft2(x, axes=(1, 2))
     exp = np.fft.rfft2(x, axes=(1, 2))
     tol = 64 * np.finfo(np.float64).eps
     assert np.allclose(res, exp, atol=tol, rtol=tol)
 
 
-@pytest.mark.parametrize(
-    "interface", [mfi.scipy_fft, mfi.numpy_fft], ids=["scipy", "numpy"]
-)
+@pytest.mark.parametrize("interface", interfaces, ids=ids)
 @pytest.mark.parametrize(
     "func", ["fftshift", "ifftshift", "fftfreq", "rfftfreq"]
 )

mkl_fft/tests/third_party/scipy/test_basic.py

@@ -7,22 +7,26 @@
 
 import numpy as np
 import pytest
-import scipy
 from numpy.random import random
 from numpy.testing import assert_allclose, assert_array_almost_equal
 from pytest import raises as assert_raises
 
 # pylint: disable=possibly-used-before-assignment
-if scipy.__version__ < "1.12":
-    # scipy from Intel channel is 1.10 with python 3.9 and 3.10
-    pytest.skip("This test file needs scipy>=1.12", allow_module_level=True)
-elif scipy.__version__ < "1.14":
-    # For python-3.11 and 3.12, scipy<1.14 is installed from Intel channel
-    # For python<=3.9, scipy<1.14 is installed from conda channel
-    # pylint: disable=no-name-in-module
-    from scipy._lib._array_api import size as xp_size
+try:
+    import scipy
+except ImportError:
+    pytest.skip("This test file needs scipy", allow_module_level=True)
 else:
-    from scipy._lib._array_api import xp_size
+    if np.lib.NumpyVersion(scipy.__version__) < "1.12.0":
+        # scipy from Intel channel is 1.10 with python 3.9 and 3.10
+        pytest.skip("This test file needs scipy>=1.12", allow_module_level=True)
+    elif np.lib.NumpyVersion(scipy.__version__) < "1.14.0":
+        # For python-3.11 and 3.12, scipy<1.14 is installed from Intel channel
+        # For python<=3.9, scipy<1.14 is installed from conda channel
+        # pylint: disable=no-name-in-module
+        from scipy._lib._array_api import size as xp_size
+    else:
+        from scipy._lib._array_api import xp_size
 
 from scipy._lib._array_api import is_numpy, xp_assert_close, xp_assert_equal
 

mkl_fft/tests/third_party/scipy/test_multithreading.py

@@ -8,7 +8,10 @@
 import pytest
 from numpy.testing import assert_allclose
 
-import mkl_fft.interfaces.scipy_fft as fft
+try:
+    import mkl_fft.interfaces.scipy_fft as fft
+except ImportError:
+    pytest.skip("This test file needs scipy", allow_module_level=True)
 
 
 @pytest.fixture(scope="module")

pyproject.toml

@@ -59,7 +59,8 @@ readme = {file = "README.md", content-type = "text/markdown"}
 requires-python = ">=3.9,<3.13"
 
 [project.optional-dependencies]
-test = ["pytest", "scipy"]
+scipy_interface = ["scipy>=1.10"]
+test = ["pytest", "scipy>=1.10"]
 
 [project.urls]
 Download = "http://github.com/IntelPython/mkl_fft"