I have three variables which I have graphed as a scatter plot. One for x, one for y, and one for whether the point is red or blue. There are clearly two clusters - one red cluster, and one blue cluster.
How do I identify the two clusters, and then set a tolerance and figure out what the rough boundary is between the two clusters (i.e. say with a tolerance of 5, any points where 50 < x < 55 and 60 < y < 65 would be considered in the boundary)? I know I could use K-means for cluster identification. But I'm not sure how to deal with the boundary problem.