How to find distance between points in every grid?

Hello, I defined a grid onto a map that I plotted with MAP library. This grid contains some elements and I know the density of each grid (which one contains what amount of elements). But now I need to find which element belongs to which grid and calculate distance between these points belonging to same grid.

Here is my code, and you can find the data and the figure attached. Thank you from now.

clear all;figure;
addpath('D:\Desktop\BOUN\JOB\Slip_Rates\Slip_Data\MAP');

LAT1=39;LAT2=42;LON1=29.0;LON2=41.0;
sf = 1;

m_proj('albers equal-area','lat',[LAT1 LAT2],'long',[LON1 LON2],'rect','on');m_gshhs_h('color',[.5 .5 .5]);hold on; 
m_grid('linewi',1,'linest','none','tickdir','in','fontsize',10);

all = load('all_velocities.txt');
lon1=all(:,1);lat1=all(:,2);ve1=all(:,3);vn1=all(:,4);

%[lon1,lat1,ve1,vn1,sve1,svn1] = textread('all_velocities.txt','%f %f %f %f %f %f'); % REFERENCE

%density of the grids
dLO = .5*2; dLA = .3636*2;

lon = [LON1:dLO:LON2];  % grid size longitude
lat = [LAT1:dLA:LAT2];  % grid size latitude

for i = 1:length(lat)
    for j = 1:length(lon)
        DENSITY(i,j) = length(find(abs(lat1-lat(i))<dLA/2 & (abs(lon1-lon(j))<dLO/2)));
    end
end

% distance between vectors in every single defined grids
z = 1;
for i = 1:length(lat)
    for j = 1:length(lon)
        ind = find(abs(lat1-lat(i))<dLA/2 & (abs(lon1-lon(j))<dLO/2));
        for k = 1:length(ind)
            points(z,:) = [lat1(ind(k)) lon1(ind(k))];
            DIST = pdist(points, 'euclidean');
            z = z+1;
        end
    end
end

m_pcolor(lon-dLO/2,lat-dLA/2,DENSITY);colormap(jet);colorbar;
m_quiver(lon1,lat1,sf.*ve1,sf.*vn1,1,'w','filled','AutoScale','off','linewidth',1.5);
hold off;

[Walter Roberson]

Why are you growing points() by one more row, then finding the distances between all of the rows so far and assigning it to DIST, and then growing points() by another row, finding the distances between all of the rows of the now larger matrix, and writing overtop of the previously calculated DIST, and so on?

And since you keep growing points(), is it correct that you want to compare the points from one i, j combination to the points with different i, j combination? Or do you only want to calculate within the block ?

[Walter Roberson]

nlat = length(lat);
nlon = length(lon);
DIST = cell(nlat, nlon);
for i = 1:nlat
    for j = 1:nlon
        ind = find(abs(lat1-lat(i))<dLA/2 & (abs(lon1-lon(j))<dLO/2));
        points = [ reshape(lat1(ind), [], 1), reshape(lon1(ind), [], 1)];
        DIST{i,j} = pdist(points, 'euclidean');
    end
end

[Sevil Cansu Yildirim]

I am sorry to ask but, in this case, is these DIST{} indicates the distances between the points in every 5x13 grid I defined? If so, thank you.

[Walter Roberson]

Yes.