scatter random points on a circle with a minimum distance and some constraints added

Hi Matlab users,

Following my previous question:

https://www.mathworks.com/matlabcentral/answers/449322-scatter-random-points-on-a-circle-with-a-minimum-distance

Now I want to add a new feature to the code. After finding the selected set of points using the code above, I want to randomly choose one of the points and move it in a random direction on the big circle. Lets name the distance that I want to move "d". "d" should not be bigger than 0.005*R. so I guess it can be "d = rand*(0.005*R);"

Also again, this little move should not make the point to be closer than 0.005*R to any other point on the circle, and also should not go out of the circle. I would highly appreciate if you could guide me to fix it.

Best,

Argu

Answer 1

[Image Analyst]

I think the code by Bruno will do what you want, or can be adapted to do so.

https://www.mathworks.com/matlabcentral/answers/453169-pseudo-random-distribution-of-points-with-minimum-distance#comment_687604

[Argumanh]

I do not understand how that code is related to what I asked. But I am trying to write my own code. Then I will post it here for some corrections.

[Image Analyst]

Not sure what "on a circle" means. Do you mean within the circle? Or on the circumference (outline, outer edge) of the circle? The answer I gave was for within a circle.

[Argumanh]

Yes I mean within the cirlce. So this is the condition I am trying to code:

so after the code give us 70 random points in the cirlce of radius 70 with minimum distance required of 5, I choose one random point(I call it MP) then I define x1,y1 for the new one. then I choose the selected point to move 150 in a random direction.

% Now we choose a random point and move it:(it is the "PM" indice)
PM = randi(70);
x1 = x;
y1 = y;

for K = 1 : 100 * P  % P=70 number of points in the cirlce
    d = (150);    % I want it to move 150 steps
theta = rand()*(360);
x1(PM) = x(PM) + d*cos(theta); % New x-coordinate
y1(PM) = y(PM) + d*sin(theta); % New y-coordinate

% Then I enforce two conditions
% 1)Distance of the new point must be less than 5:
      for i=1:P 
            ResDistances(i) = sqrt((x1(i)-x1(PM)) .^ 2 + (y1(i) - y1(PM)) .^ 2);
            if  ResDistances(i)>0 && ResDistances(i)<= 5
                break;
            end
      end
 % 2)The new point must be inside the circle: (R=70)
     if  sqrt((x1(PM)).^2 + (y1(PM)).^2) <= R 
                break;
     end
end

However this is not working, any help with that is much appreciated.

Best,

Argu

[Argumanh]

did it myself. Thanks