How to count and plot the number of points in a grid?

I have a huge data set of more than 19,00,000 points. By point I meant x and y. I am creating a 20*20 minor grid in my plot. I would like to count the number of points that fall in a single grid cell and plot/print the number (of points) in the grid itself in an another plot. I tried to look at hist3() and histcounts2() functions but, couldn't get a hold of it.

Please find attached the picture of the figure.

Please help. Thanks in advance.

[Rik]

histcounts2 was introduced in R2015b. It is in the base Matlab product. If you are using a release prior to that, you should really mention it.

If you mean you couldn't get it to work, did you read the documentation? What did you try?

[Bhanu Pratap Singh]

Currently, this is what I am doing. I am not sure, whether I am getting the right output or not. I am using MATLAB R2018a.

%% Read the file into a matrix
C = textscan(fopen('offsets-1.txt'), '%d%d%d%d%f%f%f%f%f%f%f');
% C{6}, C{7} = Easting, northing of Shot Points
% C{8}, C{9} = Easting, northing of Receiver Points
% C{10}, C{11} = Easting, northing of Midpoints Points
sx = C{6}; sy = C{7};
rx = C{6}; ry = C{7};
mx = C{6}; my = C{7};

xedges = min(rx):20:max(rx);
yedges = min(ry):20:max(ry);

nbins_x = length(xedges); nbins_y = length(yedges);

histogram2(mx, my, 'XBinEdges', xedges, 'YBinEdges', yedges, 'DisplayStyle','tile', 'ShowEmptyBins', 'off');
colorbar;

[Rik]

Why do you think there might be something wrong? I'm on mobile so I can't run your code, but nothing jumps out at me from your code.

Answer 1

[Just Manuel]

Hehe, being curious and doing the stuff mathworks slaps in your face sometimes pays off ;) (I mean the community treasure hunt)

This brought me across this approach to what you want to do:

https://blogs.mathworks.com/videos/2010/01/22/advanced-making-a-2d-or-3d-histogram-to-visualize-data-density/

Have fun watching the Video ;)

Cheers

Manuel

[Just Manuel]

Dear @Bhanu Pratap Singh

Please accept the answer, if it was of use to you.

Cheers

Manuel