In newer versions, the error report is "attempt to grow array along ambiguous dimension"
Early in the code you use
[X,Y] = meshgrid(x);
x is length 3 so your X and Y end up as 3 x 3.
Then later in your code you try to use X as having to do with your cluster positions. But because you initialized it as 3 x 3, when you use X(cluster) that is linear indexing into the 3 x 3 array. Eventually you try to assign to X(10) and that fails because it cannot figure out how to assign to the 10th linear element of a 3 x 3 array.
You should be using "clear X Y" before you reach the section where you attempt to assign to X by cluster.
You re-used a variable name for a different purpose and then you got surprised when the remaining size of the old purpose did not agree with the shape needed for the new purpose.
