Are you sure that's what you want to do? The subscript is a logical vector of length 3, subscripting a 3 x 3 matrix, so you're treating the matrix as a vector (stacked columns) and recycling the indices. The first iteration modifies 6 entries of the matrix.
It looks like you want to replace the entries in the ith column which exceed top[i] by top[i] (lost the ",i" in the subscript expression in copying, perhaps). That could be done in several ways. You can either create a matrix out of top of the same shape as z and then compare element-by-element, with pmin for example, or use the recycling rule. That latter is cleaner if z is transposed, but > t(pmin(t(z),top)) works. You could use apply as well, like > apply(z,1,function(x) pmin(x,top)) to compare each row with the vector top, but you have to transpose the result. I don't see any advantage to this, though. Reid Huntsinger -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Clark Allan Sent: Friday, May 20, 2005 10:01 AM To: [email protected] Subject: [R] R: looping hi all i have a simple question. code is displayed below. how can i use a vectorised command in order to do this (ie replace the loop)? (ie apply, lapply, sweep, etc) z<-matrix(c(1:9),3,3) top<-c(1.5,5.5,9) for (i in 1:3) z[z[,i]>top[i]]<-top[i] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
