Hi
You should be able to use hist3 and imagesc to achieve what you seek:
data = randi(1000, 5000, 2); % Create fake data. 5000x2 with values between 1:1000 (mm)
figure;
resolution = [10, 10]; % This defines the how many bins you want 1000mm/10 = 100mm bin size
[n, q] = hist3(data, resolution);
imagesc(q{:}, n');
xlabel('length [mm]');
ylabel('length [mm]');
c = colorbar;
c.Label.String = 'Amount';
If you want custom colors you have to create you own colorbar. Else try some of the premade.
