Function File: m = fht (d)
Function File: m = fht (d, n)
Function File: m = fht (d, n, dim)

Calculate the Fast Hartley Transform of real input d. If d is a matrix, the Hartley transform is calculated along the columns by default. The options n and dim are similar to the options of FFT function.

The forward and inverse Hartley transforms are the same (except for a scale factor of 1/N for the inverse Hartley transform), but implemented using different functions.

The definition of the forward hartley transform for vector d, m[K] = \sum_{i=0}^{N-1} d[i]*(cos[K*2*pi*i/N] + sin[K*2*pi*i/N]), for 0 <= K < N. m[K] = \sum_{i=0}^{N-1} d[i]*CAS[K*i], for 0 <= K < N.

fht(1:4)

See also: ifht, fft.

Package: signal