Creating Random Coordinates Inside a Fixed Points

Im asking for a random number generator inside an area like this;

Size of the rectange is 12 lengt 8 side,

for the circle the radius 2.

From that on I'm planning to create a mash area for my problem's further calculations.

[darova]

YOu can use PDE toolbox to create a mesh and export it to MATLAB workspace

[Fabio Freschi]

If you need to create a mesh outside the PDE environment you may have a look at

• mesh2d: https://it.mathworks.com/matlabcentral/fileexchange/25555-mesh2d-delaunay-based-unstructured-mesh-generation
• distmesh: https://popersson.github.io/distmesh/

Answer 1

[Fabio Freschi]

% geometry data
xMax = 12;
yMax = 8;
rCircle = 2;

% number of points
N = 1000;

% points iside the rectangle
P = bsxfun(@times,rand(N,2),[xMax yMax]);

% initial plot of all points
figure, hold on, axis equal
plot(P(:,1),P(:,2),'*');

% translate in the origin
Q = bsxfun(@minus,P,[xMax/2 yMax/2]);

% index of points outside the circle
idx = sqrt(sum(Q.^2,2)) > rCircle;

% keep points outside the circle
P = P(idx,:);

% plot points outside the circle
plot(P(:,1),P(:,2),'o');

[Hjodie]

Appreciated, thanks for the help which is that fast :)