MATLAB: The plot doesn’t show the line

graphlineplot

l=1000; %mm
a=50; %mm^2
e=100; %KN/mm^2
h=0;
X=(0:10:500);
Y=[];
o=h/l;
lp=l/cos(o);
ld=(lp+l)/l;
while h < 500
    t=e.*a.*ld./l;
    p=2.*t.*h./l;
    o=h./l;
    h=h+10;
    lp=l./cos(o);
    ld=(lp+l)./l;
    Y(h)=p;
 end
plot(x,y,'r-')
Here is my code. Am I missing something? Could someone fix it and explain to me, thank you.

Best Answer

I seee two problems:
First, you need to define ‘X’ as:
X=0:499;
Second, MATLAB is case-sensitive, so ‘x’ is different from ‘X’. (The same obviously applies to ‘y’ and ‘Y’.)
With that change and this corrected plot call:
plot(X,Y,'r-')
your plot appears.
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