Matlab has .*, so that t(x1,x2).*t(x3,x4).* t(x5,x6) but what is .* in R? Thanks. Dot. -- View this message in context: http://www.nabble.com/how-can-I-do-this-sum--tp18931693p18932274.html Sent from the R help mailing list archive at Nabble.com.