How to plot graphs with the specific time domain

Hi, i am trying to plot 3 graphs with the specific time domian. Here's my code:

t = -2*pi:0.01:2*pi;
function y = f(t)
y = (abs(t)./t+1)/2 - 2*((abs(t-pi)./(t-pi)+1)/2) + (abs(t-2*pi)./(t-2*pi)+1)/2;
endfunction
plot(t = 0:2*pi,f(t))
title("f(t)");
plot(t = -2*pi:0,-f(-t))
title("-f(-t)");
plot(t = 0:2*pi,-f(t+pi))
title("-f(t+T)");

Here's the error i got:

Below are the results that I would like to obtain. Please help. Thanks!

Answer 1

[Star Strider]

I am not certain what you want to do.

Try this:

figure
subplot(3,1,1)
plot(t((t>=0) & (t<= 2*pi)),f(t((t>=0) & (t<= 2*pi))))
ylim([-1  1])
title("f(t)");
subplot(3,1,2)
plot(t((t>=-2*pi) & (t<=0)),-f(-t((t>=-2*pi) & (t<=0))))
ylim([-1  1])
title("-f(-t)");
subplot(3,1,3)
plot(t((t>=0) & (t<= 2*pi)),-f(t((t>=0) & (t<= 2*pi))+pi))
ylim([-1  1])
title("-f(t+T)");
hold off

Experiment to get the results you want. Remember that changes in the ‘t’ vector as the independent variable must be the same in the argument to ‘f’.

[Jinquan Li]

I tried it but no graphs came out. here's what i just tried:

t = -2*pi:0.01:2*pi;

function y = f(t);

y = (abs(t)./t+1)/2 - 2*((abs(t-pi)./(t-pi)+1)/2) + (abs(t-2*pi)./(t-2*pi)+1)/2;

subplot(3,1,1)

fplot(f(t((t>=0) & (t<= 2*pi))))

ylim([-1 1])

title("f(t)");

subplot(3,1,2)

fplot(-f(-t((t>=-2*pi) & (t<=0))))

ylim([-1 1])

title("-f(-t)");

subplot(3,1,3)

fplot(-f(t((t>=0) & (t<= 2*pi))+pi))

ylim([-1 1])

title("-f(t+T)");

hold off

end

[Star Strider]

I did not use fplot in my code.

Copy and paste my code to a new script in your Editor, and run it. It will work.

[Jinquan Li]

i tried this. No graphs came out:

t = -2*pi:0.01:2*pi;

function y = f(t);

y = (abs(t)./t+1)/2 - 2*((abs(t-pi)./(t-pi)+1)/2) + (abs(t-2*pi)./(t-2*pi)+1)/2;

figure

subplot(3,1,1)

plot(t((t>=0) & (t<= 2*pi)),f(t((t>=0) & (t<= 2*pi))))

ylim([-1 1])

title("f(t)");

subplot(3,1,2)

plot(t((t>=-2*pi) & (t<=0)),-f(-t((t>=-2*pi) & (t<=0))))

ylim([-1 1])

title("-f(-t)");

subplot(3,1,3)

plot(t((t>=0) & (t<= 2*pi)),-f(t((t>=0) & (t<= 2*pi))+pi))

ylim([-1 1])

title("-f(t+T)");

hold off

end

[Star Strider]

This code:

t = -2*pi:0.01:2*pi;
% function y = f(t)
% y = (abs(t)./t+1)/2 - 2*((abs(t-pi)./(t-pi)+1)/2) + (abs(t-2*pi)./(t-2*pi)+1)/2;
% endfunction
f = @(t) (abs(t)./t+1)/2 - 2*((abs(t-pi)./(t-pi)+1)/2) + (abs(t-2*pi)./(t-2*pi)+1)/2;

figure
subplot(3,1,1)
plot(t((t>=0) & (t<= 2*pi)),f(t((t>=0) & (t<= 2*pi))))
ylim([-1  1])
title("f(t)");
subplot(3,1,2)
plot(t((t>=-2*pi) & (t<=0)),-f(-t((t>=-2*pi) & (t<=0))))
ylim([-1  1])
title("-f(-t)");
subplot(3,1,3)
plot(t((t>=0) & (t<= 2*pi)),-f(t((t>=0) & (t<= 2*pi))+pi))
ylim([-1  1])
title("-f(t+T)");
hold off

ran for me without error and produced:

I have no idea what the problem is with your running it.

[Jinquan Li]

I see. thank you so much!

[Star Strider]

My pleasure!