Using Stair plot with a For loop and If statement for ranges

I am trying to retreive an output for a for loop in stair graph format, but when I run the code with the plot either within, or without, the loop all I ever see is an empty graph. It seems as though it's only saving the final value of 't' and 'n' either way.

clc; clear;
for t=1:1:50
   n=rand;
    if n>=0 && n<0.5
        I(t)=0;
    else
        I(t)=2;
    end
% stairs(t,I(t)); hold on
end
stairs(t,I(t))

Answer 1

[Voss]

In each iteration of the for loop, t is a scalar. First t is 1, then 2, and so on until t is 50 in the last iteration. Now, after the loop is finished, t is still 50, so when you plot using t and I(t) you are in fact plotting only the final value of t and I.

You need to have all values of t available after the loop in order to plot correctly, so try this:

clc; clear;
t = 1:1:50; % t is a vector with 50 elements
for ii = 1:numel(t)
    n=rand;
    if n>=0 && n<0.5
        I(ii)=0; % could just as well use I(t(ii)) here
    else
        I(ii)=2; % and here, since t(ii) == ii
    end
end
stairs(t,I)