1 Feb 01:34 2006

### affy: How to back transform the matrix to a vector? (low-level imaging)

I am trying to transform the vector (pm and mm) extracted from <at> exprs to a matrix (2-D layout), so an image can be plotted. It works out. Now, when I back-transform the image matrix to the vector, there are some trouble. See the code below. Seems that the matrix has to be transposed somehow. Any ideas? Thanks! -Simon library (affy) data (affybatch.example) # has 3 chips x<- affybatch.example m.vector <- log2( x <at> exprs[, 2]) # take the second array x.pos <- (1:nrow(x)) - (1 + getOption("BioC")$affy$xy.offset) y.pos <- (1:ncol(x)) - (1 + getOption("BioC")$affy$xy.offset) # from vector to matrix m <- as.matrix(rev(as.data.frame(matrix(m.vector, nrow = length(x.pos), ncol = length(y.pos))))) # ???????????????? # from matrix to vector(Continue reading)