Re: [R] matrix looping accessing previous column

Using which() improves my code, but now I'm receiving some data.frame error and still does not convert the values to negative. #TAKE PART OF MATRIX CEM1_PARTIAL <- CEM1[1:10,1:10] #CEM1_PARTIAL=apply(CEM1_PARTIAL,2,as.character) #CEM1_PARTIAL <- as.numeric(as.character(CEM1_PARTIAL)) #CEM1_PART

Re: [R] matrix looping accessing previous column

That just converts my values in V3 to NA -- View this message in context: http://r.789695.n4.nabble.com/matrix-looping-accessing-previous-column-tp3165308p3165340.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.or

Re: [R] matrix looping accessing previous column

Thank you for the quick response :-). I've applied your suggestion to my code, but I still receive an error: > CEM1_PARTIAL$V3[which(CEM1_PARTIAL$V4 == "DOWN") - 1] <- > CEM1_PARTIAL$V3[which(CEM1_PARTIAL$V4 == "DOWN") - 1] * -1 Warning message: In Ops.factor(CEM1_PARTIAL$V3[which(CEM1_PARTIAL$V4

[R] matrix looping accessing previous column

Hi, I have a matrix with numbers and character. I want to evaluate each cell and change the value of the cell before it depending on the evaluation. My evaluation: if a cell had the word "down" change the cell preceding it to a negative number by multiplying that value by a -1. I am have trouble