Hello,
you have 2 way to do this in MatLab, use the evalclusters() and silhouette() to find an optimal k, you can also use the elbow method (i think you can find code in matlab community) check matlab documentation for examples, and below
% example
load fisheriris
clust = zeros(size(meas,1),6);
for i=1:6
clust(:,i) = kmeans(meas,i,'emptyaction','singleton',...
'replicate',5);
end
va = evalclusters(meas,clust,'CalinskiHarabasz')
