SciPy

scipy.fftpack.ifft

scipy.fftpack.ifft(x, n=None, axis=-1, overwrite_x=False)[source]

Return discrete inverse Fourier transform of real or complex sequence.

The returned complex array contains y(0), y(1),..., y(n-1) where

y(j) = (x * exp(2*pi*sqrt(-1)*j*np.arange(n)/n)).mean().

Parameters :

x : array_like

Transformed data to invert.

n : int, optional

Length of the inverse Fourier transform. If n < x.shape[axis], x is truncated. If n > x.shape[axis], x is zero-padded. The default results in n = x.shape[axis].

axis : int, optional

Axis along which the ifft’s are computed; the default is over the last axis (i.e., axis=-1).

overwrite_x : bool, optional

If True, the contents of x can be destroyed; the default is False.

Returns :

ifft : ndarray of floats

The inverse discrete Fourier transform.

See also

fft
Forward FFT

Notes

This function is most efficient when n is a power of two, and least efficient when n is prime.

If the data type of x is real, a “real IFFT” algorithm is automatically used, which roughly halves the computation time.

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