Plotting a Complex exponential - G(e^jw)

When plotting a function which is G(e^jw) what function would I use? As I know that for G(jw) I can use define a transfer equation etc.

Answer 1

[Rick Rosson]

N = 1024;
dw = 2*pi/N;
w = -pi:dw:pi-dw;
s = exp(j*w);
G = (s-a)./((s-b).*(s-c));

figure;
plot(w,abs(G));

figure;
plot(w,20*log10(abs(G)));

[Oleg Zhuravlev]

What are the variables a, b, c? Are they defined in a separate script?

Answer 2

[John D'Errico]

Um, what do you want to plot?

I assume that G returns a complex result, for complex input. As I hope you understand, a complex number is really a two dimensional animal. It has a real and an imaginary part. So typically when one plots complex numbers, you use the x and y axes, x for the real part, y for the imaginary part.

However, since the output is also complex in general, you will need to make a choice. Do you plot the real or imaginary part on the z axis? Or the magnitude of G, or the polar angle. Nothing stops you from making more than one plot of course.

In terms of what tool would you use, surf or contour will suffice for the task, or any of their cousins. Any tool that lets you plot in 3 dimensions.

Answer 3

[Aditya Dua]

You can either plot abs() and angle() of G(e^jw) vs. w on the same axes, or just plot G(e^jw) in the x-y plane using something like plot(real(G),imag(G),'.'). Depends on what you are trying to accomplish.

Answer 4

[abcd]

clc
clear all
close all
syms t s w
x=exp(jwt).*heaviside(t)
X=laplace(x)