Consider a signal 𝑥[𝑛] = (0.2)𝑛𝑢[𝑛]. plot the magnitude, angle, real and imaginary parts of 𝑋(𝑒𝑗𝜔). Plot 𝑋(𝑒𝑗𝜔) at 101 101 equispaced points between 0 and 𝜋. help me to find error in subplot command. all four items are not plotted.

w = [0:1:100]*pi/100;

X = exp(j*w) ./ (exp(j*w) - 0.2*ones(1,101));magX = abs (X) ; angX = angle (X) ;realX = real(X); imagX = imag(X);subplot(2,2,1); plot(w/pi,magX);

xlabel('frequency in pi units'); title('Magnitude Part');ylabel('Magnitude')subplot(2,2,2); plot(w/pi,angX); xlabel('frequency in pi units');title('AnglePart');ylabel('Radians')subplot(2,2,3);plot(w/pi,realX);

xlabel('frequency in pi units'); title('Real Part');ylabel('Real')

subplot(2,2,4); plot(w/pi,imagX); xlabel('frequency in pi units'); title('Imaginary Part'); ylabel('Imaginary')

Answer 1

[Alex Mcaulley]

Your problem is due to bad programming practices. I recommend to put each instruction in a separate line. If you do that your script works. If you don't do that you have to put a semicolon after each instruction.

w = [0:1:100]*pi/100;  
X = exp(j*w) ./ (exp(j*w) - 0.2*ones(1,101));
magX = abs (X);
angX = angle (X);
realX = real(X);
imagX = imag(X);
subplot(2,2,1);
plot(w/pi,magX);  
xlabel('frequency in pi units');
title('Magnitude Part');
ylabel('Magnitude')
subplot(2,2,2);
plot(w/pi,angX);
xlabel('frequency in pi units');
title('AnglePart');
ylabel('Radians')
subplot(2,2,3);
plot(w/pi,realX);
xlabel('frequency in pi units');
title('Real Part');
ylabel('Real')
subplot(2,2,4);
plot(w/pi,imagX);
xlabel('frequency in pi units');
title('Imaginary Part');
ylabel('Imaginary')