Uniformly distributed points generation inside quadrilateral with given points

Question

NKM 2020-5-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/524640-uniformly-distributed-points-generation-inside-quadrilateral-with-given-points

编辑： Rena Berman 2020-5-14

I have a quadrilaterla with vertices (1,0),(1,2),(2,1) and (3,4). How can I generate uniformly distributed points inside it along with plot?

2 个评论
显示无隐藏无

John D'Errico 2020-5-11

Is this a one time problem with this specific quad? Or tomorrow will you have some different quadrilateral? Or will you have a more general polygon? The reason I ask is the solution would depend on what you really need to do next.

The simple solution would be to triangulate the quadrilateral. Then generate points randomly inside the triangles, based on their area. Not difficult.

Rena Berman 2020-5-14

(Answers Dev) Restored edit

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Ameer Hamza 2020-5-11

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/524640-uniformly-distributed-points-generation-inside-quadrilateral-with-given-points#answer_431793

编辑：Ameer Hamza 2020-5-11

在 MATLAB Online 中打开

One of the way can be to find a rectangle enclosing all the vertices, create uniformly distributed random points inside the rectangle and then filter out the points using inpolygon()

x = [2 2 3 4];
y = [1 3 2 5];
% sort the vertices to create a convex polygon
X = [x.' y.'];
idx = convhull(X);
X = X(idx, :);
% find enclosing rectangle
ll_corner = [min(x) min(y)]; % lower_left corner
tr_corner = [max(x) max(y)]; % top_right corner
points = rescale(rand(10000, 2), ll_corner, tr_corner); % scale the random number
                                                       % to be inside the rectangle
idx = inpolygon(points(:,1), points(:,2), X(:,1), X(:,2));
points = points(idx, :);
figure();
ax = axes();
plot(X(:,1), X(:,2), 'LineWidth', 1)
hold on
plot(points(:,1), points(:,2), '.')