scwv.m

这是伯克里wavelet transforms一书中的例子的代码

% m file to generate scaling function and wavelet from the h filter.
% specify $h(n)$ in array called h and then call this m file.
% For D4 use h in Table 1.
sizeh=length(h); h = h/sum(h);
co=2*h;do=(-1).^(0:sizeh-1).*co(sizeh-(0:sizeh-1));
sampunit=32; sizphi=sampunit*(sizeh-1); sizpsi=sizphi;
phi=zeros(1,sizphi); psi=zeros(1,sizpsi);
phi(1:sampunit)=ones(1,sampunit);figure(1);plot((0:length(phi)-1)/sampunit,phi);
pause(5)
phitemp=zeros(1,sizphi/2); psitemp=phitemp;
for k=1:sampunit,       
   phitemp = phi(1:2:sizphi);phi=zeros(1,sizphi);
   for l=0:sizeh-1,
	
	phi(sampunit/2*l+1:sampunit/2*l+sizphi/2)=phi(sampunit/2*l+1:sampunit/2*l+sizphi/2)+co(l+1)*phitemp;
	end
	%if (rem(k,2) == 0)
        figure(1);plot((0:length(phi)-1)/sampunit,phi);
        if (k < 4)
          pause(10);
        end; %endif
 end
end
phitemp = phi(1:2:sizphi);
for l=0:sizeh-1,
	psi(sampunit/2*l+1:sampunit/2*l+sizphi/2)=psi(sampunit/2*l+1:sampunit/2*l+sizphi/2)+do(l+1)*phitemp;
end
figure(2);plot((0:length(psi)-1)/sampunit,psi);