Signal Toolkit - ifwht

Function File: ifwht (x)

Function File: ifwht (x, n)

Function File: ifwht (x, n, order)

Compute the inverse Walsh-Hadamard transform of x using the Fast Walsh-Hadamard Transform (FWHT) algorithm. If the input is a matrix, the inverse FWHT is calculated along the columns of x.

The number of elements of x must be a power of 2; if not, the input will be extended and filled with zeros. If a second argument is given, the input is truncated or extended to have length n.

The third argument specifies the order in which the returned inverse Walsh-Hadamard transform coefficients should be arranged. The order may be any of the following strings:

"sequency"

The coefficients are returned in sequency order. This is the default if order is not given.

"hadamard"

The coefficients are returned in Hadamard order.

"dyadic"

The coefficients are returned in Gray code order.

See also: fwht.