[R] color code from csv
jim at bitwrit.com.au
Sun Oct 5 12:04:44 CEST 2008
> hi folks,
> this is driving me up the wall. Apologies for posting twice in the same
> week, I'm writing up a thesis. I wish to color-code some dots in an xy
> plot. I've got a csv file with various elements, one of which is the
> color-key (with the header 'color'). If the color-key is decimal (eg.
> 1,2,3) then I can use
> plot (X ~ Y, col=data$color)
> The problem, however, is that using decimal numbers I can only produce 8
> colors. It starts to recyle them after that (so, if possible values of my
> color column are 1,2,3,4,5,6,7,8,9,10,11, the values 1 and 9 both produce
> red, 2 and 10 produce black). However, I knew I could get more colors by
> using hexadecimal (tested with the legend) So, I carefully produced a csv
> file with hexadecimal values instead of decimal ones (eg. elements in the
> column are #ffffff, #ff0000) but if I use col=data$color it doesn't work,
> the entire plot is white. If I use these set of hexadecimal values in the
> legend, it works fine and I get lovely colors.
You might want to look at color.scale in the plotrix package that
transforms numeric values into colors as well as the rainbow function
that Sarah mentioned.
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