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Function fft2

numpy/fft/_pocketfft.py:922–1014  ·  view source on GitHub ↗

Compute the 2-dimensional discrete Fourier Transform. This function computes the *n*-dimensional discrete Fourier Transform over any axes in an *M*-dimensional array by means of the Fast Fourier Transform (FFT). By default, the transform is computed over the last two axes of t

(a, s=None, axes=(-2, -1), norm=None)

Source from the content-addressed store, hash-verified

920
921@array_function_dispatch(_fftn_dispatcher)
922def fft2(a, s=None, axes=(-2, -1), norm=None):
923 """
924 Compute the 2-dimensional discrete Fourier Transform.
925
926 This function computes the *n*-dimensional discrete Fourier Transform
927 over any axes in an *M*-dimensional array by means of the
928 Fast Fourier Transform (FFT). By default, the transform is computed over
929 the last two axes of the input array, i.e., a 2-dimensional FFT.
930
931 Parameters
932 ----------
933 a : array_like
934 Input array, can be complex
935 s : sequence of ints, optional
936 Shape (length of each transformed axis) of the output
937 (``s[0]`` refers to axis 0, ``s[1]`` to axis 1, etc.).
938 This corresponds to ``n`` for ``fft(x, n)``.
939 Along each axis, if the given shape is smaller than that of the input,
940 the input is cropped. If it is larger, the input is padded with zeros.
941 if `s` is not given, the shape of the input along the axes specified
942 by `axes` is used.
943 axes : sequence of ints, optional
944 Axes over which to compute the FFT. If not given, the last two
945 axes are used. A repeated index in `axes` means the transform over
946 that axis is performed multiple times. A one-element sequence means
947 that a one-dimensional FFT is performed.
948 norm : {"backward", "ortho", "forward"}, optional
949 .. versionadded:: 1.10.0
950
951 Normalization mode (see `numpy.fft`). Default is "backward".
952 Indicates which direction of the forward/backward pair of transforms
953 is scaled and with what normalization factor.
954
955 .. versionadded:: 1.20.0
956
957 The "backward", "forward" values were added.
958
959 Returns
960 -------
961 out : complex ndarray
962 The truncated or zero-padded input, transformed along the axes
963 indicated by `axes`, or the last two axes if `axes` is not given.
964
965 Raises
966 ------
967 ValueError
968 If `s` and `axes` have different length, or `axes` not given and
969 ``len(s) != 2``.
970 IndexError
971 If an element of `axes` is larger than than the number of axes of `a`.
972
973 See Also
974 --------
975 numpy.fft : Overall view of discrete Fourier transforms, with definitions
976 and conventions used.
977 ifft2 : The inverse two-dimensional FFT.
978 fft : The one-dimensional FFT.
979 fftn : The *n*-dimensional FFT.

Callers

nothing calls this directly

Calls 1

_raw_fftndFunction · 0.85

Tested by

no test coverage detected