You could also take a look at the 'Polychrome' package
Paul
On 12/09/18 03:36, Barry Rowlingson wrote:> On Tue, Sep 11, 2018 at 11:43 AM, Duncan Murdoch <murdoch.duncan at
gmail.com>
> wrote:
>
>> On 11/09/2018 3:34 AM, Federico Calboli wrote:
>>> Hi All,
>>>
>>> I am plotting a scatterplot of 21 populations, and I am using
>> rainbow(21)[pops.col] to generate 21 colours for the plot (which
works).
>> Maybe it is because I can really process few colours at a time, but the
>> differences between the colours are not as strong as I?d like. I can
>> specify start and end for rainbow(), but if anything that looks worse
if I
>> do not just stick to 0 and 1.
>>>
>>> Is there a way of getting a set of 21 colours that maximises the
>> differences between them?
>>
>> The LAB and LUV color spaces (in the colorspace package) attempt to map
>> perceptual differences to equal distances. You could try using a grid
>> of points in one of those spaces, but not all triples are valid.
>>
>> However, 21 colours is probably too many for your purpose. If you
>> really want to distinguish 21 groups, you're likely going to have
to use
>> other characteristics as well, such as the symbol. You could plot 21
>> different letters in 5 different colours and it might work, but
it's not
>> going to be easy for viewers.
>>
>>
> The `alphabet` and `alphabet2` palettes from the `pals` package claim 26
> "distinguishable" colours:
>
> Details:
>
> The ?alphabet? palette has 26 distinguishable colors that have
> logical names starting with the English alphabet letters A, B, ...
> Z. This palette is based on the work by Green-Armytage (2010), but
> uses the names 'orange' instead of 'orpiment', and
'magenta'
> instead of 'mallow'.
>
> There are some other palettes in that help page (?alphabet) that might also
> work. But 21 colours is pushing it.
>
> Barry
>
>
>
>
>
>
>> Duncan Murdoch
>>
>>>
>>> I could pick them by hand, but that is about 15 colours more than I
know
>> (I have a detailed colourchart, but the visual differences between
>> ?skyblue? and ?slategrey? elude me when plotted as dots on a plot).
>>>
>>> Cheers
>>>
>>> F
>>> --
>>> Federico Calboli
>>> LBEG - Laboratory of Biodiversity and Evolutionary Genomics
>>> Charles Deberiotstraat 32 box 2439
>>> 3000 Leuven
>>> +32 16 32 87 67
>>>
>>>
>>>
>>>
>>>
>>> ______________________________________________
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see
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>> posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/
>> posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
paul at stat.auckland.ac.nz
http://www.stat.auckland.ac.nz/~paul/