spyrit.misc.walsh_hadamard.ifwalsh_S

spyrit.misc.walsh_hadamard.ifwalsh_S(s, ind=True)

Inverse fast Walsh S-transform of s

Args:

x (np.ndarray): n-by-1 signal. n+1 should be a power of two.

ind (bool, optional): True for sequency (default).

ind (list, optional): permutation indices. This is faster than True

when repeating the sequency-ordered transform multilple times.

Returns:

np.ndarray: n-by-1 inverse transformed signal

Examples:

Inverse S-transform of a 15-by-1 signal

>>> import spyrit.misc.walsh_hadamard as wh
>>> import numpy as np
>>> x = np.array([1, 3, 0, -1, 7, 5, 1])
>>> print(f"signal: {x}")
>>> s = wh.fwalsh_S(x)
>>> print(f"s-transform: {s}")
>>> y = wh.ifwalsh_S(s)
>>> print(f"inverse s-transform: {y}")