Matlab for the Hann-Poisson Window

function [w,h,p] = hannpoisson(M,alpha)
%HANNPOISSON  - Length M Hann-Poisson window 
Mo2 = (M-1)/2; n=(-Mo2:Mo2)';
scl = alpha / Mo2;
p = exp(-scl*abs(n));
scl2 = pi / Mo2;
h = 0.5*(1+cos(scl2*n));
w = p.*h;