Hi, What exactly is the difference between using symm=TRUE and symm=FALSE in a heatmap. More elaborately, when symm=FALSE, what does the heatmap plots because it seems like it changes the scale and makes it asymmetric, even if x is symmetric and square. Additionally, is it possible to view the matrix that the heatmap plots? Here is a sample code I have been testing: rm(list = ls()) g <- graph.full(5) %du% graph.full(5) %du% graph.full(5) g <- add.edges(g, c(1,6, 1,11, 6, 11)) adjMatrix=get.adjacency(g, sparse=FALSE) heatmap3(adjMatrix, Rowv = NA, Colv = NA, symm=FALSE) windows() heatmap3(adjMatrix, Rowv = NA, Colv = NA, symm=TRUE) Thanks, Fayez [[alternative HTML version deleted]]