%approximations close all; clear all; iter=3; [LO_D,HI_D,LO_R,HI_R] = wfilters('db2'); h=LO_R * 2 / sum(LO_R) K=length(h)-1; S=2^iter; p=ones(1,S); hu=upsam(h,S); for iter =1:iter my_conv=conv(hu,p); p=my_conv(1:2:length(my_conv)); plot(p); pause; end