summaryrefslogtreecommitdiff
path: root/silx/math/fft/fft.py
diff options
context:
space:
mode:
Diffstat (limited to 'silx/math/fft/fft.py')
-rw-r--r--silx/math/fft/fft.py96
1 files changed, 96 insertions, 0 deletions
diff --git a/silx/math/fft/fft.py b/silx/math/fft/fft.py
new file mode 100644
index 0000000..eb0d73b
--- /dev/null
+++ b/silx/math/fft/fft.py
@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2018-2019 European Synchrotron Radiation Facility
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+# ###########################################################################*/
+from .fftw import FFTW
+from .clfft import CLFFT
+from .npfft import NPFFT
+from .cufft import CUFFT
+
+
+def FFT(
+ shape=None,
+ dtype=None,
+ template=None,
+ shape_out=None,
+ axes=None,
+ normalize="rescale",
+ backend="numpy",
+ **kwargs
+):
+ """
+ Initialize a FFT plan.
+
+ :param List[int] shape:
+ Shape of the input data.
+ :param numpy.dtype dtype:
+ Data type of the input data.
+ :param numpy.ndarray template:
+ Optional data, replacement for "shape" and "dtype".
+ If provided, the arguments "shape" and "dtype" are ignored,
+ and are instead inferred from it.
+ :param List[int] shape_out:
+ Optional shape of output data.
+ By default, the data has the same shape as the input
+ data (in case of C2C transform), or a shape with the last dimension halved
+ (in case of R2C transform). If shape_out is provided, it must be greater
+ or equal than the shape of input data. In this case, FFT is performed
+ with zero-padding.
+ :param List[int] axes:
+ Axes along which FFT is computed.
+ * For 2D transform: axes=(1,0)
+ * For batched 1D transform of 2D image: axes=(0,)
+ :param str normalize:
+ Whether to normalize FFT and IFFT. Possible values are:
+ * "rescale": in this case, Fourier data is divided by "N"
+ before IFFT, so that (FFT(data)) = data
+ * "ortho": in this case, FFT and IFFT are adjoint of eachother,
+ the transform is unitary. Both FFT and IFFT are scaled with 1/sqrt(N).
+ * "none": no normalizatio is done : IFFT(FFT(data)) = data*N
+ :param str backend:
+ FFT Backend to use. Value can be "numpy", "fftw", "opencl", "cuda".
+ """
+ backends = {
+ "numpy": NPFFT,
+ "np": NPFFT,
+ "fftw": FFTW,
+ "opencl": CLFFT,
+ "clfft": CLFFT,
+ "cuda": CUFFT,
+ "cufft": CUFFT,
+ }
+
+ backend = backend.lower()
+ if backend not in backends:
+ raise ValueError("Unknown backend %s, available are %s" % (backend, backends))
+ F = backends[backend](
+ shape=shape,
+ dtype=dtype,
+ template=template,
+ shape_out=shape_out,
+ axes=axes,
+ normalize=normalize,
+ **kwargs
+ )
+ return F