Re: [ferret_users] ocean cooling palette recommended

[jagadish karmacharya <j_karmacharya@xxxxxxxxx>]

Its not very clear what your question is.

I think central palette works only when there are equal number of levels on +ve and -ve sides. If you want to associate color with fixed value then one way may be to define palette associating data values (in the first column) with colors. I have not done it myself but see http://ferret.pmel.noaa.gov/Ferret/faq/palettes-for-out-of-bounds-data for some idea. But I guess these palettes has limitled utility as they work well only for the assigned data values.

 

Jagadish

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From: Kelin Zhuang <kzhuang@xxxxxxxxxxxxxxxxx>
To: Ansley Manke <ansley.b.manke@xxxxxxxx>
Cc: "ferret_users@xxxxxxxx" <ferret_users@xxxxxxxx>; j_karmacharya@xxxxxxxxx
Sent: Friday, April 6, 2012 10:15 PM
Subject: Re: [ferret_users] ocean cooling palette recommended

Thanks for all reply.
I have a more specific question.
For example, if I use blue_darkred pal and if I use lev=(-5,5,0.5) then white is in the middle.However, If I still want white in the middle and all colors remain but the lev changes to (-5,2,0.5). How can I modify the blue_darkred.spk. Thanks!
Kelin
On 04/06/2012 12:51 PM, Ansley Manke wrote:

Hi Kelin,
A place to start is the FAQ, How can I choose a good color palette for my plot?

One thing that's not mentioned there is the  Fpalette command (from the Unix command line). Try

> Fpalette center

to find a list of the centered palettes that are in the Ferret distribution. And the main documentation has information about choosing color levels to go with a centered palette.  You'll want /LEV=c  or /LEV=vc, or a custom set of levels so that the middle level of the palette (white or a light color) is the color that represents values near zero.

Ansley

On 4/6/2012 12:09 PM, Kelin Zhuang wrote:

Dear Ansley and all,
Would you kindly recommend a palette for ocean cooling. The default rainbow pal seems not appropriate for a cold background. I prefer a zero change in the middle of white color and the coldest is blue and warmest is red. For example from -5C to 3C. Great thanks!
Kelin