matlab用于dsp

dsp实验% Program P4_3 % Zero Locations of Linear Phase FIR Filters clf; b = [1 -8.5 30.5 -63]; num1 = [b 81 fliplr(b)]; num2 = [b 81 81 fliplr(b)]; num3 = [b 0 -fliplr(b)]; num4 = [b 81 -81 -fliplr(b)]; n1 = 0:length(num1)-1; n2 = 0:length(num2)-1; subplot(2,2,1); stem(n1,num1); xlabel('Time index n');ylabel('Amplitude'); grid; title('Type 1 FIR Filter'); subplot(2,2,2); stem(n2,num2); xlabel('Time index n');ylabel('Amplitude'); grid; title('Type 2 FIR Filter'); subplot(2,2,3); stem(n1,num3); xlabel('Time index n');ylabel('Amplitu de'); grid; title('Type 3 FIR Filter'); subplot(2,2,4); stem(n2,num4); xlabel('Time index n');ylabel('Amplitude'); grid; title('Type 4 FIR Filter'); pause subplot(2,2,1); zplane(num1,1); title('Type 1 FIR Filter'); subplot(2,2,2); zplane(num2,1); title('Type 2 FIR Filter'); subplot(2,2,3); zplane(num3,1); title('Type 3 FIR Filter'); subplot(2,2,4); zplane(num4,1); title('Type 4 FIR Filter'); disp('Zeros of Type 1 FIR Filter are'); disp(roots(num1)); disp('Zeros of Type 2 FIR Filter are'); disp(roots(num2)); disp('Zeros of Type 3 FIR Filter are'); disp(roots(num3)); disp('Zeros of Type 4 FIR Filter are'); disp(roots(num4)); de'); grid; title('Type 3 FIR Filter'); subplot(2,2,4); stem(n2,num4); xlabel('Time index n');ylabel('Amplitude'); grid; title('Type 4 FIR Filter'); pause subplot(2,2,1); zplane(num1,1); title('Type 1 FIR Filter'); subplot(2,2,2); zplane(num2,1); title('Type 2 FIR Filter'); subplot(2,2,3); zplane(num3,1); title('Type 3 FIR Filter'); subplot(2,2,4); zplane(num4,1); title('Type 4 FIR Filter'); disp('Zeros of Type 1 FIR Filter are'); disp(roots(num1)); disp('Zeros of Type 2 FIR Filter are'); disp(roots(num2)); disp('Zeros of Type 3 FIR Filter are'); disp(roots(num3)); disp('Zeros of Type 4 FIR Filter are'); disp(roots(num4));