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Hi, Can somebody tell me, which is the fastest way to make comparisons between all rows in a matrix (here A) and put the results to the new symmetric matrix? I have here used cosine distance as an example, but the comparison function can be any other, euclidean dist etc. A=rbind(c(2,3),c(4,5),c(-1,2),c(5,6)) M=matrix(nrow=length(A[,1]),ncol=length(A[,1])) for(i in 1:length(A[,1])) { for(j in

Hello! Two questions: 1: I have to import a matrix of adjacency from a file of a software that is not R (for example "bloc notes" of Windows). The problem is that the matrix is not in the explicit form as 0 1 1 1 0 0 1 0 0 but it is a scattered matrix where in each row there are two nodes that have a direct path. The matrix is a b a c b a c a For example, the first row