search for: row_sums

Displaying 2 results from an estimated 2 matches for "row_sums".

2010 Dec 06
1
Sparse matrix performance question
I have a very sparse square matrix which is < 20K rows & columns and I am trying to row standardize the matrix for the rows that have non-missing value as follows: row_sums <- rowSums(M,na.rm=TRUE) nonzero_idxs <- which(row_sums>0) nonzero_M <- M[nonzero_idxs,]/row_sums[nonzero_idxs] M[nonzero_idxs,] <- nonzero_M Each line completes well under a second except the last line which takes well over 10 seconds which is simply assigning the sub-matrix of row...
2009 May 27
3
Neural Network resource
Hi All, I am trying to learn Neural Networks. I found that R has packages which can help build Neural Nets - the popular one being AMORE package. Is there any book / resource available which guides us in this subject using the AMORE package? Any help will be much appreciated. Thanks, Indrajit