[R] Data Grouping Question

[Kissell, Robert [EQRE]]

Hi,

I have a quick question regarding grouping data in R. I have the following matrix,

A =	0	1	1	0
	1	0	0	1
	1	0	0	1
	1	1	0	0
	1	0	0	1
	0	1	1	0

I would like to learn how I can group the data on unique rows of A and also count the number of times the row occurred. The command unique(A) provides a matrix with the unique rows, i.e., B

B =	0	1	1	0
	1	0	0	1
	1	1	0	0

but I am also interested in learning how I can count the number of unque rows too. The result can be in either one or two matrices, e.g.,

B =	0	1	1	0
	1	0	0	1
	1	1	0	0

Count =		1
		3
		2

or,

C =	0	1	1	0	1
	1	0	0	1	3
	1	1	0	0	2

Thanks in advance.

Rob Kissell
Robert.Kissell at Citigroup.com