I have a data frame containing sequences and I am interested in changing a few sequences in a window and the swapping the original sequence back after I have completed my analysis. My temporary data frame that I am creating seq.in.window does not like the way I am making me assignment. The variable seq.in.window gets numbers assigned to it, instead of the data contained in sequence.data. Can someone point out the mistake I am making? Thanks ../Murli x<-c("a","t","g","c") sequence.data<-structure(list(V1 = structure(c(4L, 1L, 3L, 2L, 2L, 3L, 3L, 2L, 2L, 1L, 2L, 1L, 2L, 1L, 1L, 4L, 1L, 4L, 3L, 1L), .Label = c("a", "c", "g", "t"), class = "factor"), V2 = structure(c(3L, 2L, 4L, 1L, 4L, 1L, 3L, 4L, 2L, 3L, 3L, 4L, 2L, 4L, 4L, 1L, 4L, 2L, 3L, 4L), .Label = c("a", "c", "g", "t"), class = "factor"), V3 = structure(c(3L, 3L, 3L, 3L, 3L, 1L, 4L, 2L, 1L, 3L, 1L, 1L, 1L, 2L, 1L, 4L, 1L, 4L, 1L, 4L), .Label = c("a", "c", "g", "t"), class = "factor"), V4 = structure(c(3L, 2L, 1L, 2L, 2L, 3L, 4L, 2L, 1L, 4L, 3L, 4L, 2L, 1L, 4L, 2L, 4L, 4L, 4L, 3L), .Label = c("a", "c", "g", "t"), class = "factor"), V5 = structure(c(3L, 3L, 3L, 2L, 1L, 1L, 2L, 4L, 2L, 3L, 4L, 2L, 1L, 1L, 4L, 4L, 4L, 2L, 1L, 4L), .Label = c("a", "c", "g", "t"), class = "factor"), V6 = structure(c(2L, 2L, 1L, 4L, 3L, 4L, 1L, 4L, 2L, 3L, 3L, 2L, 3L, 2L, 2L, 3L, 1L, 4L, 4L, 4L), .Label = c("a", "c", "g", "t"), class = "factor")), .Names = c("V1", "V2", "V3", "V4", "V5", "V6"), class = "data.frame", row.names = c("16", "4", "1", "9", "6", "2", "15", "19", "18", "12", "13", "91", "41", "21", "151", "14", "5", "8", "181", "121")) seq.in.window<-data.frame(matrix(0,nrow=20,ncol=5)) # Creating an empty data frame for(i in 1:20){ seq.in.window[i,1:5]<- sequence.data[i,1:5] #Can I do this assignment? print(seq.in.window[i,1:5]) rnd.seq =as.vector(sample(x,length(1:5), replace=TRUE)) sequence.data[i,5] =t(rnd.seq) print(sequence.data[i,1:5]) cat("\n") } for(i in 1:20){ sequence.data[i,1:5]=seq.in.window[i,1:5] } [[alternative HTML version deleted]]