[R] creating rainbow gradients

Kingsford Jones kingsfordjones at gmail.com
Thu Sep 18 00:20:30 CEST 2008


On second thought, this is more likely to be what you're looking for...

library(rgl)
x <- rnorm(1000)
y <- rnorm(1000)
z <- x + y
plot3d(x, y, z, col = rainbow(1000, end = 5/6)[rank(z)], size = 3)


On Wed, Sep 17, 2008 at 4:06 PM, Kingsford Jones
<kingsfordjones at gmail.com> wrote:
> On Wed, Sep 17, 2008 at 3:11 PM, Gillian Silver <haettulegur at gmail.com> wrote:
>> What would I do if I have something like:
>>
>> x <- rnorm(1:1000)
>> y <- rnorm(1:1000)
>> z <- x + y
>>
>> and I want the rainbow to increase with z? (i.e., red for lowest z...all the
>> way up to the last color in the rainbow for the highest z)
>
> Do you mean something like the following?
>
> z <- rnorm(1000, sd = sqrt(2))
> plot(z, col = rainbow(length(z), end = 5/6)[rank(z)], pch = 19)
>
>
>
>>
>> On Wed, Sep 17, 2008 at 2:05 PM, stephen sefick <ssefick at gmail.com> wrote:
>>
>>> plot(1:20, col=rainbow(20))
>>>
>>> On Wed, Sep 17, 2008 at 4:58 PM, Gillian Silver <haettulegur at gmail.com>
>>> wrote:
>>> > Hi, how can I create a rainbow gradient in R? For example, let's say I
>>> have
>>> > a plot of y = x...and I want the plot to go from red -> orange -> yellow
>>> ->
>>> > green -> blue -> etc.
>>> > Right now, I know how to do something like go from red to blue, using the
>>> > plotrix library:
>>> >
>>> > library(plotrix)
>>> > redToBlue <-
>>> >
>>> color.scale(x,redrange=c(0,1),greenrange=c(0,1),bluerange=c(0,1),extremes=c("red","blue"))
>>> > plot(x, y, col=redToBlue)
>>> >
>>> > But I can't figure out how to make the colors a rainbow. (I don't
>>> understand
>>> > how the redrange, greenrange, and bluerange parameters in color.scale
>>> work.)
>>> >
>>> > Could someone please help?
>>> >
>>> > Thanks!
>>> >
>>> >        [[alternative HTML version deleted]]
>>> >
>>> > ______________________________________________
>>> > 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.
>>> >
>>>
>>>
>>>
>>> --
>>> Stephen Sefick
>>> Research Scientist
>>> Southeastern Natural Sciences Academy
>>>
>>> Let's not spend our time and resources thinking about things that are
>>> so little or so large that all they really do for us is puff us up and
>>> make us feel like gods. We are mammals, and have not exhausted the
>>> annoying little problems of being mammals.
>>>
>>>        -K. Mullis
>>>
>>
>>        [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> 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.
>>
>



More information about the R-help mailing list