MATLAB: Showing repeat data points in XY/scatter plot

repeat data scatter

I'm trying to figure out a way to show in a scatter plot a way to make points darker or larger if they appear more than once. Lets say you have 3 points, and 2 are the exact same x,y coordinates, but plotting this you would only see 2 points that look the same on the plot. How can the ones that are repeats look different? I was trying to write a function to make new arrays with repeat data, but this is proving difficult as well.

Best Answer

%Data
x = ones(1,12);
y = [1 1 2 3 3 3 4 5 6 2 2 2];
%Engine
[uxy, jnk, idx] = unique([x.',y.'],'rows');
szscale = histc(idx,unique(idx));
%Plot Scale of 25 and stars
scatter(uxy(:,1),uxy(:,2),'p','sizedata',szscale*25)