# Plotting a Complex exponential - G(e^jw)

41 Ansichten (letzte 30 Tage)
Bill am 11 Jan. 2015
Beantwortet: abcd am 26 Okt. 2023
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.
##### 0 Kommentare-2 ältere Kommentare anzeigen-2 ältere Kommentare ausblenden

Melden Sie sich an, um zu kommentieren.

### Antworten (4)

Rick Rosson am 12 Jan. 2015
Bearbeitet: Rick Rosson am 12 Jan. 2015
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)));
##### 1 Kommentar-1 ältere Kommentare anzeigen-1 ältere Kommentare ausblenden
Oleg Zhuravlev am 31 Aug. 2023
What are the variables a, b, c? Are they defined in a separate script?

Melden Sie sich an, um zu kommentieren.

John D'Errico am 11 Jan. 2015
Bearbeitet: John D'Errico am 11 Jan. 2015
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.
##### 0 Kommentare-2 ältere Kommentare anzeigen-2 ältere Kommentare ausblenden

Melden Sie sich an, um zu kommentieren.

Aditya Dua am 11 Jan. 2015
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.
##### 0 Kommentare-2 ältere Kommentare anzeigen-2 ältere Kommentare ausblenden

Melden Sie sich an, um zu kommentieren.

abcd am 26 Okt. 2023
clc
clear all
close all
syms t s w
x=exp(jwt).*heaviside(t)
X=laplace(x)
##### 0 Kommentare-2 ältere Kommentare anzeigen-2 ältere Kommentare ausblenden

Melden Sie sich an, um zu kommentieren.

### Kategorien

Mehr zu 2-D and 3-D Plots finden Sie in Help Center und File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by