Hi, I'd like to fill an existing svg (or png) map with gradient colors. In detail: The file http://commons.wikimedia.org/wiki/File:Karte_%C3%96sterreich_Bundesl%C3%A4nder.svg should be filled with the population density data from this table: http://de.wikipedia.org/wiki/%C3%96sterreich#Verwaltungsgliederung choosing the right color saturation (or whatever). The final result should be something like this map: http://commons.wikimedia.org/wiki/Image:Bevoelkerungsdichte_-_Oesterreich.svg Is there a package or so for these two tasks (filling and color density ploting)? Thanks for your help, Thomas
fill map with gradient: package?
3 messages · Paul Murrell, Thomas Steiner
1 day later
Hi
Thomas Steiner wrote:
Hi, I'd like to fill an existing svg (or png) map with gradient colors. In detail: The file http://commons.wikimedia.org/wiki/File:Karte_%C3%96sterreich_Bundesl%C3%A4nder.svg should be filled with the population density data from this table: http://de.wikipedia.org/wiki/%C3%96sterreich#Verwaltungsgliederung choosing the right color saturation (or whatever). The final result should be something like this map: http://commons.wikimedia.org/wiki/Image:Bevoelkerungsdichte_-_Oesterreich.svg Is there a package or so for these two tasks (filling and color density ploting)?
The 'grImport' package can help with getting the SVG into R (see http://www.jstatsoft.org/v30/i04). First step is to convert the SVG to PostScript (I used InkScape - you can play around with how the text comes across, but I'm going to ignore that and concentrate on the map regions). Having done that, the following code loads the map into R and draws it ... library(grImport) PostScriptTrace("Austria-Map-withFonts.ps", charpath=FALSE) map <- readPicture("Austria-Map-withFonts.ps.xml") grid.picture(map) ... (the orientation may be 90 degrees out and you may get some warnings about character encodings; the former is easy to fix [see below] and the latter can just be ignored for now because we are ignoring the text). The next code shows the breakdown of the map into separate "paths" ... grid.newpage() picturePaths(map) ... from which we can see that the regions are the first 10 paths ... grid.newpage() grid.picture(map[1:10], use.gc=FALSE) At this point, you can use grImport to draw the regions with different fill colours, or you can just extract the x,y coordinates of the regions and go-it-alone. The following code takes the latter path, setting up 10 different colours, and drawing each region using grid.polygon(). The orientation is fixed by pushing a rotated viewport first ... colours <- hcl(240, 60, seq(30, 80, length=10)) grid.newpage() pushViewport(viewport(angle=-90), grImport:::pictureVP(map[1:10])) mapply(function(p, col) { grid.polygon(p$x, p$y, default.units="native", gp=gpar(fill=col)) }, regions, colours) Hope that helps. Paul
Thanks for your help, Thomas
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3 days later
Thanks Paul. I'm still struggeling with some beginners issues on the ps-import (windows troubles with installing ghostscript), but when I resolved them I'm sure that I can use your example code which loos great to me. Thanks a lot, Thomas 2009/11/4 Paul Murrell <p.murrell at auckland.ac.nz>:
Hi Thomas Steiner wrote:
Hi, I'd like to fill an existing svg (or png) map with gradient colors. In detail: The file http://commons.wikimedia.org/wiki/File:Karte_%C3%96sterreich_Bundesl%C3%A4nder.svg should be filled with the population density data from this table: http://de.wikipedia.org/wiki/%C3%96sterreich#Verwaltungsgliederung choosing the right color saturation (or whatever). The final result should be something like this map: http://commons.wikimedia.org/wiki/Image:Bevoelkerungsdichte_-_Oesterreich.svg Is there a package or so for these two tasks (filling and color density ploting)?
The 'grImport' package can help with getting the SVG into R (see http://www.jstatsoft.org/v30/i04). First step is to convert the SVG to PostScript (I used InkScape - you can play around with how the text comes across, but I'm going to ignore that and concentrate on the map regions). Having done that, the following code loads the map into R and draws it ... library(grImport) PostScriptTrace("Austria-Map-withFonts.ps", charpath=FALSE) map <- readPicture("Austria-Map-withFonts.ps.xml") grid.picture(map) ... (the orientation may be 90 degrees out and you may get some warnings about character encodings; ?the former is easy to fix [see below] and the latter can just be ignored for now because we are ignoring the text). ?The next code shows the breakdown of the map into separate "paths" ... grid.newpage() picturePaths(map) ... from which we can see that the regions are the first 10 paths ... grid.newpage() grid.picture(map[1:10], use.gc=FALSE) At this point, you can use grImport to draw the regions with different fill colours, or you can just extract the x,y coordinates of the regions and go-it-alone. ?The following code takes the latter path, setting up 10 different colours, and drawing each region using grid.polygon(). ?The orientation is fixed by pushing a rotated viewport first ... colours <- hcl(240, 60, seq(30, 80, length=10)) grid.newpage() pushViewport(viewport(angle=-90), ? ? ? ? ? ? grImport:::pictureVP(map[1:10])) mapply(function(p, col) { ? ? ? ? ? grid.polygon(p$x, p$y, default.units="native", ? ? ? ? ? ? ? ? ? ? ? ?gp=gpar(fill=col)) ? ? ? }, ? ? ? regions, colours) Hope that helps. Paul
Thanks for your help, Thomas
______________________________________________ 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.