1 ## Author: Paul Kienzle <pkienzle@users.sf.net> (2006)
2 ## This program is granted to the public domain.
5 ## @deftypefn {Function File} {@var{y} =} idst (@var{x})
6 ## @deftypefnx {Function File} {@var{y} =} idst (@var{x}, @var{n})
7 ## Computes the inverse type I discrete sine transform of @var{y}. If @var{n} is
8 ## given, then @var{y} is padded or trimmed to length @var{n} before computing
9 ## the transform. If @var{y} is a matrix, compute the transform along the
10 ## columns of the the matrix.
14 function x = idst (y, n)
16 if (nargin < 1 || nargin > 2)
22 if n==1, n = size(y,2); end
24 x = dst(y, n) * 2/(n+1);
29 %! x = log(gausswin(32));
30 %! assert(x, idst(dst(x)), 100*eps)