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:
- xarray_like
- Transformed data to invert. 
- nint, 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].
- axisint, optional
- Axis along which the ifft’s are computed; the default is over the last axis (i.e., - axis=-1).
- overwrite_xbool, optional
- If True, the contents of x can be destroyed; the default is False. 
 
- Returns:
- ifftndarray of floats
- The inverse discrete Fourier transform. 
 
 - See also - fft
- Forward FFT 
 - Notes - Both single and double precision routines are implemented. Half precision inputs will be converted to single precision. Non-floating-point inputs will be converted to double precision. Long-double precision inputs are not supported. - 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. - Examples - >>> from scipy.fftpack import fft, ifft >>> import numpy as np >>> x = np.arange(5) >>> np.allclose(ifft(fft(x)), x, atol=1e-15) # within numerical accuracy. True