How to draw a square with specific plot points
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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
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Accepted Answer
Image Analyst
on 8 Oct 2013
Edited: Image Analyst
on 29 Jul 2024 at 2:58
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
% Draw first, outer rectangle.
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;
% Draw the second, inner rectangle.
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, 'r-', 'LineWidth', 3);
% Define the plot region outer limits of the axes.
xlim([-0.5, 1.5]);
ylim([-0.5, 1.5]);
grid on;
axis equal % Make sure the aspect ratio is correct so that they look like squares.
2 Comments
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.
More Answers (4)
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,
Steven Lord
on 29 Jul 2024 at 4:17
x = [0 0 1 1];
y = [0 1 1 0];
P1 = polyshape(x, y);
plot(P1)
axis square
P2 = translate(scale(P1, 0.5), [0.25 0.25]);
figure
plot([P1, P2])
axis square
0 Comments
NAGENDRA KUMAR
on 12 Sep 2017
Moved: Image Analyst
on 29 Jul 2024 at 2:53
Please write this code
x = [0 0 1 1 0];
y = [0 1 1 0 0];
plot(x,y,'r', 'LineWidth',3)
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Pranav
on 29 Jul 2024 at 1:48
The IMAGE ANALYST did a great job at answering this question.
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