Re: [ferret_users] Creating difference plots with white in the colour bar

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Aisling,
The palette files are in a directory that's pointed to by the environment variable FER_PALETTES, and they can also be located by the unix command Fpalette

% Fpalette blue_darkred
* * * * * * * * in /home/porter/tmap/ferret/x86_64-linux/ppl
blue_darkred.spk:

% cat /home/porter/tmap/ferret/x86_64-linux/ppl
! Reverse of Dark Red to Blue, 18 steps, based on ColorBrewer RdYlBu_11
! http://geography.uoregon.edu/datagraphics/color_scales.htm
     0.0    14.2     0.0    85.0
     5.9     9.7    11.2    97.0
    11.8    16.0    34.2   100.0
    17.6    24.0    53.1   100.0
    23.5    34.0    69.2   100.0
    29.4    46.0    82.9   100.0
    35.3    60.0    92.0   100.0
    41.2    74.0    97.8   100.0
    47.1    92.0   100.0   100.0
    52.9   100.0   100.0    92.0
    58.8   100.0    94.8    74.0
    64.7   100.0    84.0    60.0
    70.6   100.0    67.6    46.0
    76.5   100.0    47.2    34.0
    82.4   100.0    24.0    24.0
    88.2    97.0    15.5    21.0
    94.1    85.0     8.5    18.7
   100.0    65.0     0.0    13.0

So you could make a copy of that palette and use the ideas in the message that Izidine points to.  There's more about color palettes in the FAQ's and the Ferret  Users Guide.


Ansley


On 6/8/2010 7:52 AM, Aisling Dolan wrote:

Hi everyone, 

I am trying to plot the difference between two global temperature fields. 
e.g.
fill/lev=(-inf)(-5,5,1)(inf)/palette=blue_darkred temp_mm_1_5m[d=1,l=1] - temp_mm_1_5m[d=2,l=1]

Where the difference is less than 0.5 degrees Celsius, I wanted to shade the area in white - to imply that the difference is not significant.  For consistency with earlier work I would ideally like to incorporate white into the blue_darkred palette.

Does anyone know a simple way of doing this?  Or what combination of RGB colours make up blue_darkred do that I could try and create my own palette?

Apologies if this is obvious, but I am a ferret novice!

Thanks in advance, 
Aisling   


*********************************************************
Aisling M. Dolan
PhD Student
School of Earth & Environment