xrscipy.fft.ihfft

xrscipy.fft.ihfft(x, coord, n=None, norm=None)

ihfft(x, coord, n=None, norm=None)

Parameters:

  • x (xarray object) – The data to transform.

  • coord (string) – The axis along which the transform is applied. The coordinate must be evenly spaced.

  • n (int, optional) – Length of the inverse FFT, the number of points along transformation axis in the input to use. If n is smaller than the length of the input, the input is cropped. If it is larger, the input is padded with zeros. If n is not given, the length of the input along the axis specified by axis is used.

  • norm ({"backward", "ortho", "forward"}, optional) – Normalization mode (see fft). Default is “backward”.

Returns:

out – The truncated or zero-padded input, transformed along the axis indicated by axis, or the last one if axis is not specified. The length of the transformed axis is n//2 + 1.

Return type:

complex ndarray

See also

hfft, irfft

scipy.fft.ihfft

scipy.fft.ihfft : Original scipy implementation

Notes

hfft/ihfft are a pair analogous to rfft/irfft, but for the opposite case: here, the signal has Hermitian symmetry in the time domain and is real in the frequency domain. So, here, it’s hfft, for which you must supply the length of the result if it is to be odd: * even: ihfft(hfft(a, 2*len(a) - 2) == a, within roundoff error, * odd: ihfft(hfft(a, 2*len(a) - 1) == a, within roundoff error.

Examples

>>> from scipy.fft import ifft, ihfft
>>> import numpy as np
>>> spectrum = np.array([ 15, -4, 0, -1, 0, -4])
>>> ifft(spectrum)
array([1.+0.j,  2.+0.j,  3.+0.j,  4.+0.j,  3.+0.j,  2.+0.j]) # may vary

Examples

>>> ihfft(spectrum)
array([ 1.-0.j,  2.-0.j,  3.-0.j,  4.-0.j]) # may vary