How to plot a density distribution of two variables

Hello,

i have a huge list of coordinates (x,y) which are often repeated in the list, as you can see from a short cut sample (see attachment):

Since the original huge files creates a surface plot of all these data of (x,y), I would like to plot this surface with the density variation, meaning that I would like to see in the plot where the (x,y) are repeated (high density) and where not.

Can somebody tell me which is the correct function for this?

cheers,

Nino

[sixwwwwww]

Dear Nino, attachment is missing. Please try to attach the file once again

Answer 1

[nick]

Hello Nino,

Since the file is not attached, I have used dummy data to reproduce it.

To visualize the density of repeated coordinates in a 2D plot, you can use a 2D histogram with the help of "histogram2" function, available from MATLAB 2015b onwards, as shown below:

% Sample data (replace this with your actual data)
x = [1, 2, 2, 3, 4, 4, 4, 5, 6, 6, 6, 6]; 
y = [1, 1, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7]; 

numBinsX = 100;
numBinsY = 100;

figure;
histogram2(x, y, [numBinsX, numBinsY], 'DisplayStyle', 'tile', 'ShowEmptyBins', 'on');
colorbar;
xlabel('X');
ylabel('Y');
title('Density Plot of (x, y) Coordinates');

colormap('hot');
grid on; 
axis equal tight; 

You can refer to the documentation of 'histogram2' to know more about it using the following command in MATLAB command window :

doc histogram2

Hope this helps!