Inverse Fast Walsh-Hadamard transform
y = ifwht(x)
y = ifwht(x,n)
y = ifwht(x,n,ordering)
y = ifwht(x) returns the coefficients of
the inverse discrete fast Walsh-Hadamard transform of the input
x is a matrix, the inverse fast Walsh-Hadamard
transform is calculated on each column of
inverse fast Walsh-Hadamard transform operates only on signals with
length equal to a power of 2. If the length of
less than a power of 2, its length is padded with zeros to the next
greater power of two before processing.
y = ifwht(x,n) returns the
inverse discrete Walsh-Hadamard transform, where
be a power of 2.
y = ifwht(x,n,ordering) specifies the ordering
to use for the returned inverse Walsh-Hadamard transform coefficients.
To specify the ordering, you must enter a value for the length
to use the default behavior, specify an empty vector (
n. Valid values for the ordering are the following
|Coefficients in order of ascending sequency value, where each row has an additional zero crossing. This is the default ordering.|
|Coefficients in normal Hadamard order.|
|Coefficients in Gray code order, where a single bit change occurs from one coefficient to the next.|
 Beauchamp, Kenneth G. Applications of Walsh and Related Functions: With an Introduction to Sequency Theory. London: Academic Press, 1984.
 Beer, Tom. "Walsh Transforms." American Journal of Physics. Vol. 49, 1981, pp. 466–472.