Please give a simple example of the input data and output that you desire. It is difficult to understand from you partial codes what you mean. For example what is Y ?
Are you trying to find add values from pairs of rows ? If so, please see my posting "pairwise difference operator" where I wanted to find the differences between pairs of columns. http://tolstoy.newcastle.edu.au/R/help/04/07/1633.html Otherwise, please send a sample input and output. Thank you. Regards, Adai On Wed, 2005-01-26 at 11:40 +0400, Jacques VESLOT wrote: > Dear all, > > I have a matrix X with 47 lines and say 500 columns - values are in {0,1}. > I'd like to compare lines. > > For that, I first did: > > for (i in 1:(dim(X)[1]-1)) > for (j in (i+1):dim(X)[1]) { > Y <- X[i,]+Y[j,] > etc. > > but, since it takes a long time, I would prefer avoding loops; > for that, my first idea was to add this matrix: > > X1=X[,rep(1:46,46:1)] > > to this one: > > res=NULL > for (i in (2:47)) res=c(res,i:47) > > X2=X[,res] > > (Is it a nice alternative way ?) > Is there a way to create the second matrix X2 without a loop, such as for X1 > ? > > Thanks in advance, > > Jacques VESLOT > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
