# How to draw a square with specific plot points

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Paul on 8 Oct 2013
I'm trying to create two squares, one larger one, and the other within it.
I attempted to create one using matrices. I create one with x = [0 0 1 1] and y = [0 1 1 0]
I wanted a line to connect each one of the points, to thus create a line. However, when I did that, I only received three lines connect between the dots for some reason. The bottom points (0,0) and (1,0) for some reason were not connected. I then attempted to make a second square, and the same thing happened, with the two lower points in regards to their Y points did not connect. I tried using the rectangle function as well, but can't get a square within a square to appear. Any help would be great. Thanks
NAGENDRA KUMAR on 12 Sep 2017
Please write this code x = [0 0 1 1 0]; y = [0 1 1 0 0]; plot(x,y,'r', 'LineWidth',3)

Image Analyst on 8 Oct 2013
Edited: Image Analyst on 8 Oct 2013
You need 5 points - the last one is to "close off" the square, otherwise it won't be closed because you didn't draw the line back to the starting point. So, try this
x1=0;
x2=1;
y1=0;
y2=1;
x = [x1, x2, x2, x1, x1];
y = [y1, y1, y2, y2, y1];
plot(x, y, 'b-', 'LineWidth', 3);
hold on;
x1=0.25;
x2=.75;
y1=0.25;
y2=.75;
x = [x1, x2, x2, x1, x1];
y = [y1, y1, y2, y2, y1];
plot(x, y, 'b-');
xlim([-1, 2]);
ylim([-1, 2]);
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Image Analyst on 8 Oct 2013
I think the way I did it is easier to understand than rectangle. In my mind I just visualize starting at the upper left corner and marching around the square in a clockwise fashion. First I do the x's then I do the y's. And so it's really quick for me to construct the 5 element x and y matrices.

Camilo Malagon Nieto on 8 May 2019
Worth to say that there is a function now to make a rectangle and smooth the corners.
Cheers,