Glad if it helps. check out this page of examples for tikz,
http://www.texample.net/tikz/examples/feature/shadings/ If you do choose this route, you could perhaps read the new wiki page on importing graphics in a R plot, http://wiki.r-project.org/rwiki/doku.php?id=tips:graphics-misc:display-images (you'll want to convert the result of Tikz into a bitmap format first, with imagemagick for example). As for the pure R graphics solution, you'll have to play with Grid viewports (and perhaps the gridBase package if your "Figure" is using base graphics). Can you post a minimal, self-contained, reproducible example of what you're trying to achieve to the list? baptiste 2009/6/25 Kexin Ji <kex...@gmail.com> > Hi, > > The triangle looks great!! > And thanks for mentioning the TeX package Tikz! Maybe I'll check it out > later. > The only problem is that I need to append this color-gradient triangle into > a another Figure I'm working on. But when I try to do that, this wonderful > triangle overwrites the other one. Have tried to append it with not much > luck.. > Much appreciation to your help though!!! > > Kexin > > > On 6/25/09, baptiste auguie <baptiste.aug...@gmail.com> wrote: >> >> Hi, >> >> I don't think the fill parameter can be a colour gradient. You'll need to >> create small polygons, each with its own fill (200, say). Try this, >> >> x= c(0, 0.5, 1) >> y= c(0.5, 1, 0.5) >> grid.polygon(x=x, y=y, gp=gpar(fill="grey90", col="grey90")) >> >> xx <- seq(range(x)[1],range(x)[2], length=100) >> yy <- rep(max(y), length(xx)) >> cols <- colorRampPalette(c("green", "lightgray"))(length(xx)) >> >> for(ii in seq_along(xx[-length(xx)])) { >> >> grid.clip(x=xx[ii], y=0.5, >> width= xx[ii+1], >> height=1, >> just="bottom") >> >> grid.polygon(x=c(0, 0.5, 1), y=c(0.5, 1, 0.5), gp=gpar(fill=cols[ii], >> col=NA)) >> } >> >> Note that the situation would become rather more complicated for a >> gradient at some angle (see ?grobX if you need to). >> >> If you're free to choose an external tool to produce this, the TeX package >> Tikz has good support for gradients and clipping. >> >> HTH, >> >> baptiste >> >> Kexin Ji wrote: >> >>> Hi, >>> >>> I wonder whether there is a way to generate a polygon (a triangle in my >>> case) with color gradient using grid.polygon() in package grid? >>> >>> I tried something like >>> >>> library(grid) >>> grid.polygon(x=c(0, 0.5, 1), y=c(0.5, 1, 0.5), gp=gpar(col=NA, >>> fill=colorRampPalette(c("green", "lightgray"), >>> space="Lab")(200))) >>> >>> But am only getting a triangle filled with color green, whereas the aim >>> is a triangle of color gradient from green to lightgray. >>> >>> Can grid.polygon() generate a color gradient, or am I being mistaken? >>> >>> Best to my knowledge, is it true that R currently doesn't contain any >>> other function that might generate a polygon with color gradient? >>> >>> Thank you! >>> >>> Kexin >>> >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> 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. >>> >>> >>> >> >> >> -- >> _____________________________ >> >> Baptiste Auguié >> >> School of Physics >> University of Exeter >> Stocker Road, >> Exeter, Devon, >> EX4 4QL, UK >> >> Phone: +44 1392 264187 >> >> http://newton.ex.ac.uk/research/emag >> ______________________________ >> >> > -- _____________________________ Baptiste Auguié School of Physics University of Exeter Stocker Road, Exeter, Devon, EX4 4QL, UK Phone: +44 1392 264187 http://newton.ex.ac.uk/research/emag ______________________________ [[alternative HTML version deleted]]
______________________________________________ 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.
