% -*- texinfo -*-
% @deftypefn{Function File} {m = } fht ( d, n, dim )
% @cindex linear algebra
% The function fht calculates Fast Hartley Transform
% where @var{d} is the real input vector (matrix), and @var{m}
% is the real-transform vector. For matrices the hartley transform
% is calculated along the columns by default. The options
% @var{n},and @var{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,
% @math{
% 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. }
%
% @example
% fht(1:4)
% @end example
% @seealso{ifht,fft}
% @end deftypefn