rowcount

Counts the number of rows in LOOKUPVALUES that matches each row in VALUES and returns the counts.

COUNTS = ROWCOUNT(VALUES, LOOKUPVALUES)

Written in c, so the operation is fast. Type "mex rowcount.c" in matlab before use.

You might need a free compiler if it was not installed with your matlab:
http://www.mathworks.com/support/compilers/R2012b/win64.html