How to plot complex signal

I'm very new to MatLab, how do i write a program in MatLab to plot : x(t) = cos (t) + j sin (t)

I was told it should be a circle but I'm seeing sinusoidal signal....

Thks in advance.

Mac. Goh

Answer 1

[Image Analyst]

Try this

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;

t = linspace(0, 2*pi, 90);
j = sqrt(-1);
complexSignal = cos(t) + j*sin (t)
% Get the real component and plot it on the x axis
x = real(complexSignal);
y = imag(complexSignal);
plot(x, y, 'bo-', 'LineWidth', 2);
grid on;
title('Plot of cos(t) + j*sin (t)', 'Fontsize', fontSize);
xlabel('Real Component', 'Fontsize', fontSize);
ylabel('Imaginary Component', 'Fontsize', fontSize);
axis square;
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);

Answer 2

[Star Strider]

You have to plot the real parts and imaginary parts:

t = linspace(0,2*pi);
x = @(t) cos (t) + j*sin (t);

figure(1)
plot(real(x(t)), imag(x(t)))
grid
axis equal
xlabel('Re\{x\}')
ylabel('Im\{x\}')

Answer 3

[Onimisi]

V=240             % Voltgae across both loads

V = 240

SL1r=120000       % Real Power consumed by load 1

SL1r = 120000

STr=400000        % Total real power consumed 

STr = 400000

pf1=0.8            % Power Factor of both Loads

pf1 = 0.8000

pf2= 0.96           % Power of only load 1 leading

pf2 = 0.9600

theta1=acosd(pf1)

theta1 = 36.8699

theta2=acosd(pf2)

theta2 = 16.2602

b=theta1

b = 36.8699

c=theta2

c = 16.2602

j=sqrt(-1)

j = 0.0000 + 1.0000i

complexST=(cosd(b))+(j*sind(b))

complexST = 0.8000 + 0.6000i

complexSL=(cosd(c))+(j*sind(-c))

complexSL = 0.9600 - 0.2800i

ST=(STr/pf1)*complexST

ST = 4.0000e+05 + 3.0000e+05i

SL1=(SL1r/pf2)*complexSL

SL1 = 1.2000e+05 - 3.5000e+04i

SL2=ST-SL1

SL2 = 2.8000e+05 + 3.3500e+05i

[Image Analyst]

@Onimisi I think you meant to post this as your own question since your post does not seem to be an Answer to @Tiam Huat Goh's 8 year old question.

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