HI All sorry if this question has already been asked but I couldn't find anything that answered my question I have 24 columns of data that I'm trying to plot in heatmap.2 (gregmisc) and I'm having difficulty ordering them except in numerical sequence: I have transposed my matrix so it will appear with the dendrogram I want appearing at the top of the heatmap If I use either of these orders the ordering works: order <- c(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24) order2 <- c(24,23,22,21,20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1) using the command: heatmap.2(tmatrix, clusteredmatrixasdendrogram, col=bluered600, dendrogram="column", scale="none", trace="none", Rowv=order) however If I start mixing the numbers up e.g: order3 <- c(1,4,7,10,2,5,8,11,3,6,9,12,13,16,19,22,14,17,20,23,15,18,21,24) or order4 <- c(24,21,18,15,23,20,17,14,22,19,16,13,12,9,6,3,11,8,5,2,10,7,4,1) The heatmap is reordered but NOT how I have specified: The actual order it returns in either case is the same: 1,5,9,2,6,10,3,7,11,4,8,12,13,17,21,14,18,22,15,19,23,16,20,24 which I'm completely confused about as I'm not plotting a dendrogram for the rows or letting the heatmap function draw its own so where is it getting the order from ? and is it possible to plot it like I'm trying to ? My second question is also from the gregmisc package I'm using bluered600 <- bluered(600) to specify the range of colors plotted my data ranges from -60 to +80 but I would like to specify that the colours range from blue to red with white being zero however because of the unequal distribution zero is shifted into the red area (hope that makes sense) I know I can specify colors for "low" "medium" and "high", in some graphics functions but this isn't what I'm trying to do unless my data is evenly distributed i.e -60 to +60 I can't plot exactly how I want to If anyone has any ideas that would be fantastic Cheers Jason -- -------------------------------- Jason Skelton Pathogen Microarrays Wellcome Trust Sanger Institute Hinxton Cambridge CB10 1SA Tel +44(0)1223 834244 Ext 7123 Fax +44(0)1223 494919