Hi Katrin,
your problem is not related to maptools, rather to the base function
"colorRampPalette". In my opinion the easiest way to get what you want is to
use colorRamp:
Vector=c(2,3,4,5,6)
color.ramp <- colorRamp(c('white','black'))
map.colors <- color.ramp(Vector/10)
The 10 refers to the maximum value that you specified. You just have to adjust
the colors.
HTH
Jannis
--- schaber <kscha...@ipp.mpg.de> schrieb am Di, 21.9.2010:
> Von: schaber <kscha...@ipp.mpg.de>
> Betreff: [R] Colorramp in Maptools, how to choose min and max values for the
> fg= argument
> An: r-help@r-project.org
> Datum: Dienstag, 21. September, 2010 15:42 Uhr
>
> Hello,
>
> I am using maptools for plooting geographical data.
> The colour of the region indicates some region dependent
> value (population for example).
>
> I pass the colours of the regions to the plot.Map function
> by defining the foreground colour:
>
> jet.colors = colorRampPalette(c("#00007F", "blue",
> "#007FFF", "cyan", "#7FFF7F", "yellow", "#FF7F00",
> "red", "#7F0000"))
> n=100
> cols <- jet.colors(n)
> Intervalls = cut(as.numeric(Vector),n, na.rm=TRUE)
> fgs <-cols[Intervalls] ## is there some
> option/possibility here to choose colours differently ??
> plot.Map(Shape.map, fg=fgs, ol=NA, bty="n", xlab="",
> ylab="", xaxt="n", yaxt="n")
>
> My problem is the following: I would like to choose minimal
> and maximal value of the colour palette, different from the
> minimal and maximal values of the Vector. For example:
> Vector=c(2,3,4,5,6), but the maximal colour should
> correspond to 10 and the minimal to 0.
>
> I know, that maptools is not the most actual solution to
> plot maps, but I am building on an old code and therefore do
> not want to change it.
>
> I would very much appreciate any help or hints!!
> Katrin
>
>
> -----Integrierter Anhang folgt-----
>
> ______________________________________________
> 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.
>
______________________________________________
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.
