# how can i draw input rectangular shape with specific iterations

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sandy jeak on 19 Dec 2015
Commented: Star Strider on 19 Dec 2015
n=100
for k=1:n
if k<=25
r(k)=1
elseif k>25&k<=50
r(k)=-1
elseif k>50&k<=75
r(k)=1
else
r(k)=-1
end
end
plot (k,r(k)) This appears when running: But I want this figure: ##### 2 CommentsShowHide 1 older comment
Image Analyst on 19 Dec 2015
In general, you would not use & in that situation (your "if" test), you'd use &&, though in this case it won't matter.

Star Strider on 19 Dec 2015
sqwv = @(x) 1.*(((x > 0) & (x < 25)) | ((x > 50) & (x < 75))) - 1.*(((x > 25) & (x < 50)) | ((x > 75) & (x < 100)));
x = 0:100;
y = sqwv(x);
figure(1)
plot(x, y,'-b')
axis([0 100 -1.5 1.5])

Image Analyst on 19 Dec 2015
You can use repmat(), like I do in my attached demo.
Or, if you have the Signal Processing Toolbox, you can use the square() function:
x = square(t,duty) generates a square wave with specified duty cycle, duty, which is a number between 0 and 100. The duty cycle is the percent of the period in which the signal is positive.
Star Strider on 19 Dec 2015
I did a version of the repmat approach in how can i draw this figure earlier.