MATLAB: Inter distance between point to be more than a certain number

randomsensor_network

Hi, I want to randomnly deploy points on region. The randomn deployment should continue until the points are at a certain distance apart (say >=20m) to all other points.
I used the code below, but the code only ensures adjacent points are >=20m. i.e distance (point 1 to point 2)>=20, distance (point 2 to point 3)>=20 etc.
BUT
I want distance from piont 1 to all other point >=20, same applies to point 2,3 and 4.
n=4;  % number of ponts
 x.ev=randperm(100,n); % x coordinate of point
 y.ev=randperm(100,n);%  y coordinate of point
 for i= 2:1:n;
    d.you(i)=sqrt( (x.ev(i)-x.ev(i-1)).^2 + (y.ev(i)-y.ev(i-1)).^2 );                         % calculate inter-distance btw points starting from the second point
 end
 d.you(1)=sqrt( (x.ev(1)-x.ev(n)).^2 + (y.ev(1)-y.ev(n)).^2 );                    % distance from the last to the fist point.
 
q=2;
while (d.you(q)-d.you(q-1)>=20) & (d.you(q)-d.you(q+1)>=20) 
  
    x.ev=randperm(100,n);
    y.ev=randperm(100,n);
   
    d.you(q)=sqrt( (x.ev(q)-x.ev(q+1)).^2 + (y.ev(q)-y.ev(q+1)).^2 );
     q=q+1;
    
end
%display(d.you)
plot(x.ev, y.ev, 'ok')
Pls, help

Best Answer

You can try my demo, that I've posted before. It's a pretty simple "try and reject or accept" method, but it's intuitive and well commented. Adapt as needed:
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format short g;
format compact;
fontSize = 20;
% Define how many points you want to place.
maxPoints = 500;
% Define counter for how many actually get placed.
numberOfPoints = 0;
% Define fail safe, how many iterations you want to keep trying before quitting.
maxIterations = 1000 * maxPoints;
loopCounter = 1;
% Define how close points can come to other points before being rejected.
minClosestDistance = 0.1;
% Declare arrays to hold the x and y coordinate values.
x = nan(1, numberOfPoints);
y = nan(1, numberOfPoints);
while numberOfPoints < maxPoints && loopCounter < maxIterations
	% Get a random point.
	xPossible = rand();
	yPossible = rand();
	if numberOfPoints == 0
		% First point automatically is valid.
		numberOfPoints = numberOfPoints + 1;
		x(numberOfPoints) = xPossible;
		y(numberOfPoints) = yPossible;
		continue;
	end
	% Find distances between this point and all others.
	distances = sqrt((x-xPossible) .^ 2 + (y - yPossible) .^ 2);
	if min(distances) >= minClosestDistance
		% It's far enough away from all the other points, or it's the first point.
		% Include it in our list of acceptable points.
		numberOfPoints = numberOfPoints + 1;
		x(numberOfPoints) = xPossible;
		y(numberOfPoints) = yPossible;
	end
	% Increment the loop counter.
	loopCounter = loopCounter + 1;
end
% Crop away points we were not able to get.
x = x(1:numberOfPoints); % Crop to valid points.

y = y(1:numberOfPoints); % Crop to valid points.
% Plot the points we were able to get.
plot(x, y, 'b.', 'MarkerSize', 15);
grid on;
xlabel('X', 'FontSize', fontSize);
ylabel('Y', 'FontSize', fontSize);
caption = sprintf('Demo of Placing %d Random Points with Min Distance of %.2f', numberOfPoints, minClosestDistance);
title(caption, 'FontSize', fontSize);
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off') 
% Tell user what we were a ble to achieve.
message = sprintf('Found %d points in %d tries', numberOfPoints, loopCounter)
helpdlg(message);
Capture.PNG
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