I know this answer is really late, but I dont think this post was answered properly.
It seems like such obvious thing to want to do, you would think it would be easy... Well, it is! Once you know how (of course). Hooray! This took me ages to figure this out too! The answer is writen right there in the help file, but it isnt obvious. This is the code from the help file ?filled.contour : ------------------------------------------------ # Annotating a filled contour plot a <- expand.grid(1:20, 1:20) b <- matrix(a[,1] + a[,2], 20) filled.contour(x = 1:20, y = 1:20, z = b, plot.axes={ axis(1); axis(2); points(10,10) }) ------------------------------------------------ Instead of "points(10,10)" add whatever you want to plot! So to add contour lines use this instead: ------------------------------------------------ # Adding contour lines to a filled contour plot a <- expand.grid(1:20, 1:20) b <- matrix(a[,1] + a[,2], 20) filled.contour(x = 1:20, y = 1:20, z = b, plot.axes={ axis(1); axis(2); contour(x = 1:20, y = 1:20, z = b, add=T) }) ------------------------------------------------ Done! Happy plotting. -- View this message in context: http://r.789695.n4.nabble.com/Filled-contour-plot-showing-labeled-isolines-tp3056437p4639849.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@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.