How to plot a Step function?

I am trying to generate a code to plot a step function that depends on t.

I am proceding the following way, but I get an error every time I run it,

 clc,clear

 t = [-100 : 100]';
 tt = [t - 1];

 for ii = 1 : 201
    if t(ii) >= 0
        t(ii) = 1;
    else
        t(ii) = 0;
    end
end

 for i = 1 : 201
    if tt(i) >= 0
        tt(i) = 1;
    else
        tt(i) = 0;
    end
end

 t1 = [-100 : 100];
 y = t1 .* (t - tt);

 plot(y,t1)

What I want is that for the input t, when t is >= 0 the value of the function is 1, and for everything else 0 and then plot the results.

Answer 1

[Walter Roberson]

stairs(t, t >= 0)