Create NxN Haar Matrix

Question

I can't find a definition for generating an un-normalized NxN Haar matrix. So what is the equation?

see: http://en.wikipedia.org/wiki/Haar_wavelet

Thx, Chris

Answer 1

Thx all. Wikipedia gives the 'equation':

I've wrote a recursive solution for generating an un-normalized NxN Haar matrix in octave.

function [h] = haar(n)
h = [1];
if n > 2
    h = haar(n/2);
endif
% calculate upper haar part
h_n = kron(h,[1,1]); 
% calculate lower haar part 
h_i = kron(eye(length(h)),[1,-1]);
% combine parts
h = [h_n; h_i];
endfunction

disp(haar(8));