R help - Jul 2023 - CIE Diagram with wavelengths tick marks

Hi,

I'm assuming that by CIE Diagram, you mean the 1931 2 deg standard.  Tables
of these (and other CIE standards) can be found at the site http://www.cvrl.org
maintained by Andrew Stockman.  You can find and download these classic CIE data
and more modern versions from there.

Since you have plotted the spectrum locus of the chromaticity diagram (I'm
supposing), you ought to be able to just pick off the wavelengths that you want
and add a small point or a small line as a tick mark.  If you want it oriented,
you'll have to do a little calculation to get the direction perpendicular to
the spectrum locus at each wavelength, but that's not too complicated.

I recently needed a figure for a talk and downloaded the 2 deg 1931 data from
the above website and used points to indicate specific wavelengths that
interested me.  The code is below:

d <- read.csv("ciexyz31_1.csv", header = FALSE, stringsAsFactors =
TRUE)
names(d) <- c("Wavelength", "X", "Y",
"Z")
d$x <- with(d, X/(X + Y + Z))
d$y <-  with(d, Y/(X + Y + Z))

par(pty = "s")
plot(y ~ x, d, type = "l", axes = 'FALSE',
	xlim = c(0, 1), ylim = c(0, 1))
lines(y[c(1, nrow(d))]~ x[c(1, nrow(d))], d)
axis(1, seq(0, 1, 0.2))
axis(2, seq(0, 1, 0.2))
lines(c(0, 1), c(1, 0), col = "blue", lwd = 2, lty = 2)

points(d[d$Wavelength == 555, ]$x, d[d$Wavelength == 555, ]$y, pch = 16, col =
"green")
points(d[d$Wavelength == 589, ]$x, d[d$Wavelength == 589, ]$y, pch = 16, col =
"yellow")
points(d[d$Wavelength == 670, ]$x, d[d$Wavelength == 670, ]$y, pch = 16, col =
"red")

Good luck.

best,

Ken


# Hy,

# for plotting CIE Diagrams i found Package pavo with function cieplot. 
# That works fine.
# Now i want to have wavelength tick marks as well around the plotting area.
# Is there a way to do so, also other ways/Pakages to plot are welcome.

# My sample Code:
   # library(pavo)

   # coldat2 <- as.data.frame(matrix(rep(1/3, 3), nrow = 1, ncol = 3))

   # # Make sure this dataset works with the cieplot() function
   # attr(coldat2, "clrsp") <- "CIEXYZ"
   # colnames(coldat2) <- c("x", "y", "z")

   # cieplot(coldat2, col="white", main="CIE Test Plot")



# Best regards
# Tilmann



     
  
 
  ___
  Kenneth Knoblauch
 Inserm U1208
 Stem-cell and Brain Research Institute
 18 avenue du Doyen L?pine
 69500 Bron
 France
 tel: +33 (0)4 72 91 34 77
 fax: +33 (0)4 72 91 34 61
 portable: +33 (0)6 84 10 64 10
 https://sbri.fr/public-profile/63/single-member/

Hy Ken,

Thanks for your answer.
Your assumptions are correct, i wan to plot a CIE 1931 2 deg standard.
I am aware of the possibility to calculate the tick marks and its 
orientation by some calculation.
But before that, i wanted to ask whether there is something ready out there.

Ans thanks for the Code, it helped me on another problem.

best

Tilmann


On 20.07.23 14:42, Kenneth Knoblauch wrote:
> Hi,
> 
> I'm assuming that by CIE Diagram, you mean the 1931 2 deg standard. 
Tables of these (and other CIE standards) can be found at the site
http://www.cvrl.org maintained by Andrew Stockman.  You can find and download
these classic CIE data and more modern versions from there.
> 
> Since you have plotted the spectrum locus of the chromaticity diagram
(I'm supposing), you ought to be able to just pick off the wavelengths that
you want and add a small point or a small line as a tick mark.  If you want it
oriented, you'll have to do a little calculation to get the direction
perpendicular to the spectrum locus at each wavelength, but that's not too
complicated.
> 
> I recently needed a figure for a talk and downloaded the 2 deg 1931 data
from the above website and used points to indicate specific wavelengths that
interested me.  The code is below:
> 
> d <- read.csv("ciexyz31_1.csv", header = FALSE,
stringsAsFactors = TRUE)
> names(d) <- c("Wavelength", "X", "Y",
"Z")
> d$x <- with(d, X/(X + Y + Z))
> d$y <-  with(d, Y/(X + Y + Z))
> 
> par(pty = "s")
> plot(y ~ x, d, type = "l", axes = 'FALSE',
> 	xlim = c(0, 1), ylim = c(0, 1))
> lines(y[c(1, nrow(d))]~ x[c(1, nrow(d))], d)
> axis(1, seq(0, 1, 0.2))
> axis(2, seq(0, 1, 0.2))
> lines(c(0, 1), c(1, 0), col = "blue", lwd = 2, lty = 2)
> 
> points(d[d$Wavelength == 555, ]$x, d[d$Wavelength == 555, ]$y, pch = 16,
col = "green")
> points(d[d$Wavelength == 589, ]$x, d[d$Wavelength == 589, ]$y, pch = 16,
col = "yellow")
> points(d[d$Wavelength == 670, ]$x, d[d$Wavelength == 670, ]$y, pch = 16,
col = "red")
> 
> Good luck.
> 
> best,
> 
> Ken
> 
> 
> # Hy,
> 
> # for plotting CIE Diagrams i found Package pavo with function cieplot.
> # That works fine.
> # Now i want to have wavelength tick marks as well around the plotting
area.
> # Is there a way to do so, also other ways/Pakages to plot are welcome.
> 
> # My sample Code:
>     # library(pavo)
> 
>     # coldat2 <- as.data.frame(matrix(rep(1/3, 3), nrow = 1, ncol = 3))
> 
>     # # Make sure this dataset works with the cieplot() function
>     # attr(coldat2, "clrsp") <- "CIEXYZ"
>     # colnames(coldat2) <- c("x", "y",
"z")
> 
>     # cieplot(coldat2, col="white", main="CIE Test
Plot")
> 
> 
> 
> # Best regards
> # Tilmann
> 
> 
> 
>       
>    
>   
>    ___
>    Kenneth Knoblauch
>   Inserm U1208
>   Stem-cell and Brain Research Institute
>   18 avenue du Doyen L?pine
>   69500 Bron
>   France
>   tel: +33 (0)4 72 91 34 77
>   fax: +33 (0)4 72 91 34 61
>   portable: +33 (0)6 84 10 64 10
>   https://sbri.fr/public-profile/63/single-member/
>      
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