how can i remove this error in my program?

% frequency response of a tree structured QMF Filters clf; %Type in the low pass filter coefficients B1=input('Filter coefficients='); B1=[ B1 fliplr(B1)]; %Generate the complementary high pass filter L=length(B1); for k=1:L; B2(k) = ((-1)^k) * B1(k); end %Determine the coefficients of the four filters B10=zeros(1, 2*length(B1)); B10([1 : 2: length(B10)])= B1; B11=zeroes(1, 2*length(abs(B2))); B11([1: 2: length(B11)]) = B2; C0=conv(B1,B10); C1=conv(B1,B11); C2=conv(B2,B10); C3=conv(B2,B11); % determine the frequency responses [H0z,w] = Freqz(C0,1,256); h0= abs(H0z); M0=20*Log10(h0); [H1z,w] = Freqz(C1,1,256); h1= abs(H1z); M1=20*Log10(h1); [H2z,w]=freqz(C2,1,256); h2= abs(H2z); M2=20*Log10(h2); [H3z,w] = Freqz(C0,1,256); h3= abs(H3z); M3=20*Log10(h3); plot(w/pi,M0,'-',w/pi,M1,'--', w/pi,M2,'--',w/pi,M3,'-'); grid xlabel('\omega/\pi'); ylabel('gain, dB')

[DuckDuck]

First of all you have to submit the code in the right form. There is a

Code

tag in the editor.

Answer 1

[Star Strider]

It’s not necessary to run your code (I didn’t) to see the problem. MATLAB is case-sensitive, so convert ‘Freqz’ to ‘freqz’, ‘Log10’ to ‘log10’ and it should at least run.