Hi: I want to create a polygon encircling a graph. For this i use convex hull to get the coordinate points for polygon. g <- barabasi.game(10) L<-layout.fruchterman.reingold(g) temp1 <- chull(L) temp1 <- c(temp1, temp1[1]) plot(g, layout=layout.fruchterman.reingold) But when i plot the polygon with the code below, the polygon dosen't encircle the graph. polygon(L[temp1, ], col = "#0000FFAA") How can I plot a polygon circling a graph? Regards: John
layout.fruchterman.reingold(g) returns a random result, so you want to call it once and use the one return value. Also, I think you need to avoid the rescaling that plot.igraph does. It looks like you need to explicitly specify xlim and ylim if you do that, but I may not have looked long enough at it. plot(g, layout=L, rescale=FALSE, xlim=range(L[,1]), ylim=range(L[,2])) polygon(L[temp1, ], col = "#0000FFAA") Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf > Of email > Sent: Thursday, November 14, 2013 10:04 AM > To: r-help at r-project.org > Subject: [R] polygon circling a graph > > Hi: > > I want to create a polygon encircling a graph. For this i use convex > hull to get the coordinate points for polygon. > > g <- barabasi.game(10) > L<-layout.fruchterman.reingold(g) > temp1 <- chull(L) > temp1 <- c(temp1, temp1[1]) > plot(g, layout=layout.fruchterman.reingold) > > > But when i plot the polygon with the code below, the polygon dosen't > encircle the graph. > > polygon(L[temp1, ], col = "#0000FFAA") > > How can I plot a polygon circling a graph? > > Regards: > John > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Please post the packages from which 'barabasi' and 'layout.fruch....' originate (not to mention whatever the plot() method is for whatever class your 'g' is). Further, without seeing what your data look like we have no way of knowing whether you've fed the appropriate elements of "L" to chull. email mail wrote> Hi: > > I want to create a polygon encircling a graph. For this i use convex > hull to get the coordinate points for polygon. > > g <- barabasi.game(10) > L<-layout.fruchterman.reingold(g) > temp1 <- chull(L) > temp1 <- c(temp1, temp1[1]) > plot(g, layout=layout.fruchterman.reingold) > > > But when i plot the polygon with the code below, the polygon dosen't > encircle the graph. > > polygon(L[temp1, ], col = "#0000FFAA") > > How can I plot a polygon circling a graph? > > Regards: > John > > ______________________________________________> R-help@> mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.-- View this message in context: http://r.789695.n4.nabble.com/polygon-circling-a-graph-tp4680479p4680484.html Sent from the R help mailing list archive at Nabble.com.