[R] intersection of two matrices

[T Joshi]

Hi,
I have two matrices as follow:
matrix A =

a=matrix(c(c("abc","abc","bcd","bcd","bce","bce"),c("a1","d2","d1","d2","a1","a2")),6,2)

and matrix B which contains pair of values :
 b=matrix(c(c("a1","a2"),c("a1","d2")),2,2)

 In short, I wish to find out pairs of values in matrix a[,2] having
same value in a[,1], which occur as a row in matrix b, so that the
output becomes :
abc
bce, or

even better
abc a1 d2
bce a1 a2

 How can I do that?
cheers,
Joshi

_________________________________

Ms Tejal Joshi

Researcher
Center for Biological Sequence Analysis
Technical University of Denmark
Kemitorvet, Building 208
DK-2800 Kgs. Lyngby, Denmark
Phone: +45 4525 6148
tejal at cbs.dtu.dk
www.cbs.dtu.dk