Hi, i need to get the parameters (at least coordinates) of a graph after layouting it with Rgraphviz. i am trying to add a rectangle to every node in a graph. for a "simple" graph it works fine (i.e. for the first node): g <- randomGraph(letters[1:10], 1:4, 0.2) plot(g, main = "Example Graph") gl <- agopen(g,name="name") gv <- AgNode(gl) x<-getNodeXY(gv[[1]])$x y<-getNodeXY(gv[[1]])$y rect(x+30,y,x+40,y+30) but after layouting the graph i get the old coordinates (before layouting) for the graph nodes: names(nLabels)?<-?nLabels?<-?nodes(g) nBorderCols <- rainbow(length(nLabels)) names(nBorderCols) <- names(nLabels) attrs?=?list(node=list(fixedsize=FALSE),graph=list(rankdir="LR")) nodeRenderInfo(g) <- list(label=nLabels, col=nBorderCols) g <- layoutGraph(g,?attrs=attrs) g<-renderGraph(g) x<-getNodeXY(gv[[1]])$x y<-getNodeXY(gv[[1]])$y rect(x+30,y,x+40,y+30) i had a look at wolfgang hubers imageMap function and tried to recalculate the usr coordinates but that does not work: usr <- par("usr") w <- getY(upRight(boundBox(gl))) h <- getX(upRight(boundBox(gl))) x.u2p = function(x) {(x-usr[1])/diff(usr[1:2])*w} y.u2p = function(y) {(usr[4]-y)/diff(usr[3:4])*h} x <- x.u2p(x) y <- y.u2p(y) rect(x,y,x+10,y+30) i am missing something here but do not have a clue were. thanks in advance, Laurin ------------------------------------------ Dipl.-Ing. Laurin Mueller University Assistant at the Institute for Bioinformatics and Translational Research UMIT - University for Health Sciences, Medical Informatics and Technology Eduard Wallnoefer-Zentrum 1, 6060 Hall in Tyrol, Austria T +43(0)50 8648 3868, F + 43(0)50 8648 673868 E laurin.mueller at umit.at, W http://bioinf.umit.at