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The assignment of the colors to the hex values is wrong and I do not understand why. I sorted the hex colors before adding them to the data frame data which is then used in the ggplot2 function. I thought that would fix the problem but it did not. I also created the vector col which contains the hex as well as the rgb color values which I actually want to have as the legend but I am also struggling to get this working

library(ggplot2)
df <- structure(list(x = 1:15, y = 1:15, cols_hex = c(
  "#00B0F6", "#00BA38",
  "#00BCD8", "#00BF7D", "#00C0AF", "#619CFF", "#6BB100", "#A3A500",
  "#B983FF", "#C99800", "#E58700", "#E76BF3", "#F8766D", "#FD61D1",
  "#FF67A4"
)), class = "data.frame", row.names = c(NA, -15L))


ggplot(NULL) +
  geom_point(data = df, aes(x = x, y = y, colour = cols_hex))

The red color which as a RGB value of (248, 118, 109) and a hex value of F8766D is assigned the hex value of 00B0F6 in the legend

Dan Bonachea
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user969113
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  • related https://stackoverflow.com/questions/15804504/how-to-conditionally-highlight-points-in-ggplot2-facet-plots-mapping-color-to – tjebo Aug 11 '22 at 14:24

1 Answers1

12

As you want to supply color names to argument colour= and display also a legend for this argument, you should add scale_colour_identity() to your last line in function. This scale ensures that values supplied will be interpreted as actual color values. Adding of argument breaks=cols_hex in function scale() will ensure ordering of names in legend.

ggplot(NULL) +     
geom_point(data=data, aes(x=x, y=y, colour=cols_hex), size=size, alpha=alpha) + 
        scale_colour_identity(guide="legend",breaks=cols_hex)

enter image description here

Didzis Elferts
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  • yes, that seems to work. I removed the sort from sort(hcl(h=hues, l=65, c=100)[1:n]) so that the colors in the plots in its "natural" way. However, in the legend, the colors are sorted in alphabetical order. Is it somehow possible to match the plot and legend order? – user969113 Feb 18 '13 at 11:25
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    Updated my solution. This will work if you do not have function sort() in cols_hex<-... – Didzis Elferts Feb 18 '13 at 11:42
  • Yes, perfect. that's how I tried to get it. Thank you very much! :) – user969113 Feb 18 '13 at 11:45