Hi, I am using Rgraphviz to create protein interaction graphs. I am looking for a way to highlight the outcome of four experiments, measuring protein quantities, in my graph. This would be 4 different colors for each protein node. There is an option in Rgraphviz to draw custom nodes as shown in the tutorial with pieGlyph. I would like to create a custom node function that is square-shaped and is composed of 4 equally-sized subsquares with different colors. Similar to a heatmap like this one : mat <- matrix(c(1,2,3,4),nrow=2) heatmap.2(mat,dendrogram="none",trace="none",key=FALSE,labRow=FALSE ,labCol=F ALSE) Thanks for any suggestion or hint. Karl Schon geh?rt? WEB.DE hat einen genialen Phishing-Filter in die Toolbar eingebaut! [1]http://produkte.web.de/go/toolbar References 1. http://produkte.web.de/go/toolbar