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Re: Plot colors [message #84985 is a reply to message #84984]

Thu, 20 June 2013 11:25

Mats Löfdahl
Messages: 263
Registered: January 2012

Senior Member

On 2013-06-20 19:24, Michael Galloy wrote:
> On 6/20/13 12:59 AM, Mats Löfdahl wrote:
>> What are your favorite colors for overplotting several data sets in the
>> same diagram? (I'm assuming Coyote graphics here.) You'd want them to be
>> easy to tell apart and to have a good and similar contrast against the
>> (white) background.
>>
>> For two colors it's easy: red and blue.
>>
>> But already for three colors, if you add green you get something with
>> less contrasty. And for more colors, if you add the complement colors
>> cyan, magenta, and yellow, both yellow and cyan have the same problem.
>> So then I usually inspect the color names in cgcolor and pick darker
>> versions of the too light colors and some redder version of yellow. And
>> if I need more than six I don't really know what to do...
>>
>> So, what is a good strategy? Do you have a good list that you always
>> use, and truncate it to the needed length? Or do you start the list
>> differently depending on how long it has to be? Has anybody written a
>> function for this? Something like
>>
>> function plotcolors, index, Ncolors
>>
>>
>> /Mats
>
> This is what the qualitative color tables in the Brewer color tables are
> for.
>
> Checkout color tables 27-34 in the Brewer color tables (the second set
> of color tables) on:
>
> http://docs.idldev.com/mglib/vis/color/mg_loadct.html
>
> To use one of these, say 27, just do:
>
> mg_loadct, /brewer, 27
>
> and then just use COLOR=0, COLOR=1, ... COLOR=11 (color table 27 has 12
> values).
>
> The Brewer color tables are included in IDL now, but they interpolated
> intermediate values for the qualitative color tables, so you have to use
> something like the following to get the 5th of the 12 values in a color
> table:
>
> COLOR=5 * 256 / 12

Brewer table 32 (Dark2) might be useful. Maybe 29 (Set1) as well. The
rest of them look like they include colors that are too bright for lines
on a white background.

The Dark2 colors look similar to the colors David suggested. Are they
the same? Or how would I refer to them in the cgcolor naming scheme? How
about the Set1 colors?

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[Message index]

		Plot colors By: Mats Löfdahl on Wed, 19 June 2013 23:59
		Re: Plot colors By: David Fanning on Thu, 20 June 2013 05:28
		Re: Plot colors By: Mats Löfdahl on Thu, 20 June 2013 08:44
		Re: Plot colors By: David Fanning on Thu, 20 June 2013 08:52
		Re: Plot colors By: David Fanning on Thu, 20 June 2013 09:10
		Re: Plot colors By: Mark Piper on Thu, 20 June 2013 09:54
		Re: Plot colors By: David Fanning on Thu, 20 June 2013 09:55
		Re: Plot colors By: Jim Pendleton on Thu, 20 June 2013 20:22
		Re: Plot colors By: David Fanning on Thu, 20 June 2013 20:28
		Re: Plot colors By: Michael Galloy on Thu, 20 June 2013 10:24
		Re: Plot colors By: Mats Löfdahl on Thu, 20 June 2013 11:25
		Re: Plot colors By: allisonjaynes on Tue, 09 July 2013 15:56
		Re: Plot colors By: Chip Helms on Wed, 10 July 2013 10:24
		Re: Plot colors By: David Fanning on Wed, 10 July 2013 10:29

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