Plotting a Step Function

The following function f(t,T,x) returns the following. 1 if qT ≤ t < (q + x)T 0 if (q + x)T ≤ t < (q + 1)T

I know this is a step function and I think it involves using heaviside, however I have no idea really where to start in order to plot the function. q, x and T are to be defined by me. THis is the code I have so far:

function v=pwm(t,T,d)
d = 0.5;
T= 0.01;
k = 1;
t=linspace(0,0.2,100);
v(k*T<=t<k+d) = 1;
v((k + d)*T <= t < (k + 1)*T) = 0;
plot(t,v)

q I changed for k (q=k) and x = d.

[Jan]

Where to start what? What is your question? What do you want to do with this function?

[Adam Makin]

Sorry you are right I should be much more specific, I wanted to plot the function.

[Jan]

Sorry, I didn't want to let you be sorry. Questions for clarifications are usual in the forum, because it is the nature of question, that some details are not clear to the asking person. :-)

Answer 1

[Star Strider]

Try this:

f = @(t,T,x,q) (1.*((q.*T <= t ) & (t < (q+x).*T))) + (0.*(((q+x).*T <= t) &  (t < (q+1).*T)));

q = 1;
x = 0.5;
T = 0.01;
t = linspace(0,0.2,100);

figure(1)
plot(t, f(t,T,x,q), '-r')
axis([xlim    0  1.1])
grid

Answer 2

[Jan]

What about this:

t = [q*T, (q + x) * T, (q + x) * T, (q + 1) * T];  % [EDITED, Typo fixed]
y = [1, 1, 0, 0];
plot(t, y)

This is a line through 4 points. Is this sufficient to plot the function, if you define q, T and x accordingly? Note that 0 < x < 1 seems to be required.

If you want something else, please explain the difference to this simple approach.

[Adam Makin]

sorry trying to run this I receive the error:

Error using plot Vectors must be the same length.

[Jan]

@Adam: Sorry, a typo.

t = [q*T, (q + x) * T, (q + x) * T, (q + 1) * T];
        ^  comma instead of colon

Is the idea of my suggestion clear?