idst(a)

Calculate the inverse sine transform of vector 'a'.

function out = idst(a)
% IDST calculate the inverse sign transform of vector a.
y = zeros(length(a)+1,1);
N = length(y);
for m = 1:length(a)
y = y + a(m) * sin(m * pi * (0:N-1)' / (N - 1));
end
out = y;
end