how can i calculate a complex polygon with coordinates in matlab ?

5 views (last 30 days)
Hi,
how can I calculate A complex polygon in Matlab?
image shows what I need to calculate in Matlab. do you guys have any code for that ? or are there any Matlab command which can calculate it by coordinates?
thanks in advance
  4 Comments
ADNAN KIRAL
ADNAN KIRAL on 19 Oct 2020
thanks for your reply.
calculation of the area !.
I have a large number of coordinates. If I can code it in Matlab. I will replace with my coordinates. So that I need to know how to calculate the area of such shape.

Sign in to comment.

Accepted Answer

Ameer Hamza
Ameer Hamza on 19 Oct 2020
The equation in your comment can be written in MATLAB like this
A = 1/2*sum(x(1:end-1).*y(2:end)-y(1:end-1).*x(2:end));
  7 Comments
Ameer Hamza
Ameer Hamza on 19 Oct 2020
You can try something like this
X;
Y;
A = zeros(1, numel(X)-2);
for i = 1:numel(A)
x = X(1:i+2);
y = Y(1:i+2);
A(i) = 1/2*sum(x(1:end-1).*y(2:end)-y(1:end-1).*x(2:end));
end

Sign in to comment.

More Answers (2)

Durganshu
Durganshu on 19 Oct 2020
You can use polyarea for accomplishing your task. The documentation is here:
Hope that helps!
  1 Comment
ADNAN KIRAL
ADNAN KIRAL on 19 Oct 2020
thanks for reply.
one more question please ? how can I get coordinate vs. area ( at the end, I need to know how the area is increasing with coordinate change)
I have tried "cumsum" Matlab command, but it did not work. it gave the total area. thanks

Sign in to comment.


Steven Lord
Steven Lord on 19 Oct 2020
If you want to do more than just compute its area I would use polyshape for that.
>> x = [7 7 5 3 -5 0 -8 2 -4];
>> y = [-7 3 -6 3 3 8 3 -3 -8];
>> P = polyshape(x, y);
>> plot(P)
There are a number of questions you can ask about a polyshape and a number of operations you can perform on one.

Categories

Find more on Elementary Polygons in Help Center and File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!