Re: [R] ColorRamp different from ColorRampPalette
Try the rgb function in the grDevices library.
pal.cr<-colorRamp( c("blue", "white", "red"), space = "rgb")
plot(rep(0,40),pch=16,col=rgb(pal.cr((0:40)/40),max=255))
Troy
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Re: [R] ColorRamp different from ColorRampPalette
Thanks Hadley,
Is it the solution you would recommend ?
rgb(pal.cr((0:40)/40), maxColorValue=255)
Etienne
hadley wrote:
>
> Look at the output of pal.cr((0:40)/40)
> Hadley
>
> On Fri, Apr 17, 2009 at 2:42 PM, Etienne B. Racine
> wrote:
>>
>> I try to use ColorRamp as ColorRampPalette (i.e. with the same gradient),
>> but
>> it seems there is a nuance that I've missed.
>>
>> pal.crp<-colorRampPalette( c("blue", "white", "red"), space = "rgb")
>> plot(rep(0,40),pch=16,col=pal.crp(40))
>> # is great
>>
>> But, using the same gradient with colorRamp is giving erratic colors.
>>
>> pal.cr<-colorRamp( c("blue", "white", "red"), space = "rgb")
>> plot(rep(0,40),pch=16,col=pal.cr((0:40)/40))
>> # is not great
>>
>> >From the help : "colorRamp returns a function that maps values between 0
>> and
>> 1 to colors" ...colors I guess taken from the gradient, but I don't get
>> the
>> gradient.
>>
>> Etienne
>>
>> --
>> View this message in context:
>> http://www.nabble.com/ColorRamp-different-from-ColorRampPalette-tp23104641p23104641.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> __
>> R-help@r-project.org mailing list
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>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
>
> --
> http://had.co.nz/
>
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Re: [R] ColorRamp different from ColorRampPalette
Look at the output of pal.cr((0:40)/40)
Hadley
On Fri, Apr 17, 2009 at 2:42 PM, Etienne B. Racine wrote:
>
> I try to use ColorRamp as ColorRampPalette (i.e. with the same gradient), but
> it seems there is a nuance that I've missed.
>
> pal.crp<-colorRampPalette( c("blue", "white", "red"), space = "rgb")
> plot(rep(0,40),pch=16,col=pal.crp(40))
> # is great
>
> But, using the same gradient with colorRamp is giving erratic colors.
>
> pal.cr<-colorRamp( c("blue", "white", "red"), space = "rgb")
> plot(rep(0,40),pch=16,col=pal.cr((0:40)/40))
> # is not great
>
> >From the help : "colorRamp returns a function that maps values between 0 and
> 1 to colors" ...colors I guess taken from the gradient, but I don't get the
> gradient.
>
> Etienne
>
> --
> View this message in context:
> http://www.nabble.com/ColorRamp-different-from-ColorRampPalette-tp23104641p23104641.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.
>
--
http://had.co.nz/
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[R] ColorRamp different from ColorRampPalette
I try to use ColorRamp as ColorRampPalette (i.e. with the same gradient), but
it seems there is a nuance that I've missed.
pal.crp<-colorRampPalette( c("blue", "white", "red"), space = "rgb")
plot(rep(0,40),pch=16,col=pal.crp(40))
# is great
But, using the same gradient with colorRamp is giving erratic colors.
pal.cr<-colorRamp( c("blue", "white", "red"), space = "rgb")
plot(rep(0,40),pch=16,col=pal.cr((0:40)/40))
# is not great
>From the help : "colorRamp returns a function that maps values between 0 and
1 to colors" ...colors I guess taken from the gradient, but I don't get the
gradient.
Etienne
--
View this message in context:
http://www.nabble.com/ColorRamp-different-from-ColorRampPalette-tp23104641p23104641.html
Sent from the R help mailing list archive at Nabble.com.
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and provide commented, minimal, self-contained, reproducible code.
