The following 1460 x 1460 matrix can be throught of as 16 distinct 365 x 365 matrices. I'm trying to set off-diaganol terms in the 16 sub-matrices with indices more than +/- 5 (days) from each other to zero using some for loops. This works well for some, but not all, of the for loops. The R code I"m using follows. For some reason the third loop below zero's-out everything in the sub-quadrant it is targeting, which is readily observable when viewing the matrix ("View(MAT)").
library(Matrix) MAT<-matrix(rnorm(1460*1460,mean=0,sd=1),nrow = 1460, ncol = 1460) #works great for (i in 1:365) { SEQ <- (i - 5):(i + 5) SEQ <- SEQ[SEQ > 0 & SEQ < 366] MAT[(1:365)[-SEQ], i] <- 0 } #works great for (i in 1:365) { SEQ <- (i - 5):(i + 5) SEQ <- SEQ[SEQ > 0 & SEQ < 366] MAT[(1:365)[-SEQ], i + 365] <- 0 } #zero's out everything, including main-diagonal and near-main-diagonal terms??? for (i in 731:1095) { SEQ <- (i - 5):(i + 5) SEQ <- SEQ[SEQ > 730 & SEQ < 1096] MAT[(731:1095)[-SEQ], i + 365] <- 0 } View(MAT) I'm not sure why the third FOR loop above is not leaving the main-diagonal and near-main-diagonal terms alone? -- View this message in context: http://r.789695.n4.nabble.com/setting-off-diagonals-to-zero-tp4656407.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.