Re: [ferret_users] grayscale palette

[Paul Young <paul.young@xxxxxxxxxxxxxxxx>]

Hi James,

You can define your own palette for this purpose. You can have a look at the information in the user's guide for information about this, but it sounds like you need to define a palette 'by_values', which is where you associate a particular colour with a contour level value. Start of by creating a .spk file and have something like

RGB_Mapping_By_value
!SetPt Red     Green    Blue

at the top of the file. You can then fill in your levels in the first column, followed by the colour you'd like to associate with that level, expressed at percentage R, G and B, in the next three columns. For example, dark gray is something like 30 30 30 and light gray is 75 75 75. Have a look at the grayscale.spk palette file in your ferret installation (probably somewhere like /bin/ferret/ppl/) for more inspiration and play around 'til you get what you want.

Hope this helps,

Paul





On Fri, 2006-12-15 at 20:59, jimmyc@iastate.edu wrote:
> Hi All-
> I need to make a color plot gray.
>
> My values cross 0 and are NOT symmetric.
> Is there a way to specify a grayscale such that the grays are skewed:
> 1. for the positive values go light to medium gray
> 2. for the negative values go medium to light
> all in one palette?
> Thanks for any advice.

-- 
Paul Young	

Centre for Atmospheric Science
Department of Chemistry
University of Cambridge
Lensfield Road
Cambridge, CB2 1EW, UK

Tel: +44 (0)1223 763 814
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http://www.atm.ch.cam.ac.uk/cas
http://www.atm.ch.cam.ac.uk/~paul