Plotting rgb proportions in R

I apologize for the late reply after the holidays. I really appreciate all
the data visualization suggestions. The scatterplot works very well, but I
do have >400 specimen with at least 5-20 colors each, so a stacked
barchart of each specific color proportion would be most useful to show
uniformity within each specimen. Below is an example of what I would like
to do, but instead of generic colors, I am hoping to plot the actual RGB
proportions for each.
[image: image.png]

On Wed, Dec 19, 2018 at 5:28 AM PIKAL Petr <petr.pikal at precheza.cz> wrote:

Hi

-----Original Message-----
From: R-help <r-help-bounces at r-project.org> On Behalf Of Bert Gunter
Sent: Wednesday, December 19, 2018 5:26 AM
To: Jim Lemon <drjimlemon at gmail.com>
Cc: R-help <r-help at r-project.org>
Subject: Re: [R] Plotting rgb proportions in R

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.

From which I would recommend ggtern. Sometimes a bit tricky but quite
handy, especially when you consider some grouping.

Cheers
Petr

-- 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 at 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 at 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]]

[[alternative HTML version deleted]]