[R] Plotting rgb proportions in R

[Jim Lemon]

I was probably a bit obscure and should have written "convert your
0-255 values to 0-1". As Bert notes, you can't get a sensible ternary
plot if your values do not sum to 1. scatterplot3d does a pretty good
job, if you run the example.


Jim

On Wed, Dec 19, 2018 at 3:26 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:
>
> 3-d Proportions must sum to 1and are thus actually 2-d and should preferaby be plotted as a ternary plot. Several r packages will do this for you, e.g. package Ternary. Search "ternary plots" on rseek.org for others.
>
> -- Bert
>
>
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along and sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>
>
> On Tue, Dec 18, 2018 at 3:10 PM Jim Lemon <drjimlemon using gmail.com> wrote:
>>
>> Hi Tasha,
>> I may be right off the track, but you could plot RGB proportions on a
>> 3D plot. The easiest way I can think if would be to convert your 0-255
>> values to proportions:
>>
>> rgb_prop<-read.table(text="Red Green Blue pct
>> 249 158 37 56.311
>> 249 158 68 4.319
>> 249 158 98 0.058
>> 249 128 7 13.965
>> 249 128 37 12.87
>> 188 128 37 0.029
>> 249 128 68 0.161
>> 188 128 68 0.015
>> 188 98 7 0.029
>> 219 128 7 2.773
>> 219 128 37 2.583
>> 188 98 68 0.058
>> 219 128 68 0.525
>> 249 188 37 0.876
>> 249 188 68 1.08
>> 219 98 7 0.482
>> 249 188 98 0.015
>> 249 158 7 3.852",header=TRUE)
>> rgb_prop$Red<-rgb_prop$Red/255
>> rgb_prop$Green<-rgb_prop$Green/255
>> rgb_prop$Blue<-rgb_prop$Blue/255
>> library(scatterplot3d)
>> scatterplot3d(rgb_prop[,1:3],cex.symbols=sqrt(rgb_prop[,4]),
>>  color=rgb(rgb_prop[,1],rgb_prop[,2],rgb_prop[,3]),pch=19)
>>
>> then plot the RGB values on a 3D scatterplot. I have included
>> arguments to make the symbols the actual RGB colors that you specify
>> and their size proportional to the square root of the percentages.
>>
>> Jim
>>
>> On Wed, Dec 19, 2018 at 5:17 AM Tasha O'Hara <tasha.eileen using gmail.com> wrote:
>> >
>> > Hello,
>> >
>> > I am trying to plot specific rgb color proportions of a marine specimen in
>> > a stacked plot using R and I was looking for some help. I have several
>> > rgb proportions per specimen (an example of one is below).  I've run into
>> > different examples of people using vegan or grDevices. Can anyone help with
>> > this?
>> >
>> > Red    Green  Blue   %
>> > 249 158 37 56.311
>> > 249 158 68 4.319
>> > 249 158 98 0.058
>> > 249 128 7 13.965
>> > 249 128 37 12.87
>> > 188 128 37 0.029
>> > 249 128 68 0.161
>> > 188 128 68 0.015
>> > 188 98 7 0.029
>> > 219 128 7 2.773
>> > 219 128 37 2.583
>> > 188 98 68 0.058
>> > 219 128 68 0.525
>> > 249 188 37 0.876
>> > 249 188 68 1.08
>> > 219 98 7 0.482
>> > 249 188 98 0.015
>> > 249 158 7 3.852
>> >
>> >         [[alternative HTML version deleted]]
>> >
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>>
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>> and provide commented, minimal, self-contained, reproducible code.