Using Delaunay triangulation to approximate the area
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Hi,
I try to use delaunay triangulation but it also connected the boundary point
As you an see the X shape, thats what I wanted only, not the square too.
thank you
2 Comments
John D'Errico
on 14 Nov 2018
Edited: John D'Errico
on 14 Nov 2018
Why did you need to ask this question twice? As I showed the last time you asked the question, you cannot use a Delaunay triangulation to do what you want, at least not without understanding how to code an alpha shape.
madhan ravi
on 14 Nov 2018
please don‘t ask the same question twice , this discourages the answerers who answer the question
Answers (1)
KSSV
on 14 Nov 2018
xy = rand(5000,2);
k = (sqrt(sum((xy - [1 .5]).^2,2)) < 0.3) | ...
(sqrt(sum((xy - [0 .5]).^2,2)) < 0.3) | ...
(sqrt(sum((xy - [0.5 1]).^2,2)) < 0.3) | ...
(sqrt(sum((xy - [0.5 0]).^2,2)) < 0.3);
xy(k,:) = [];
x = xy(:,1) ; y = xy(:,2) ;
idx = boundary(x,y) ; % gives boundary
plot(x,y,'.r')
hold on
plot(x(idx),y(idx),'b')
A = polyarea(x(idx),y(idx))
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