assigning shapes to samples in kmeans algorithm

Hello,

I am using matlabs built in kmeans function for clustering my emg data into two classes. I got the plot but, I need to add an indiacator for a corresponding time series to make some analysis. for e.g. I want to add * for first ten samples, + for next 10 samples and so on. Can somebody suggest some method ?

For more clarification,

1) i have a matrix 117 X 1

2) through class separation i got three classes, different sizes

3) i want to plot the first ten samples of matrix(1) with a definite shape, irrespective of the class.

4) and similar action on next samples

The code that I used :

i1 = find ( idx == 1 );
x1 = y(i1,:);
plot( x1(:,1), 'r*' )

here y is the original matrix and x1 is the matrix made from first index