It's not exactly clear what you mean by this.
1. For variables that have both positive and negative values (like a field of anomalies), you might want to color positive values red, negative values blue, and near-zero values white (or peraps light gray). In that case use a palette something like:
0 0 100 100
20 20 20 100
45 100 100 100
55 100 100 100
80 100 20 20
100 100 100 0
An alternative is to lightly shade the near-zero values light gray, which would distinguish them from missing values:
0 20 20 100
49 85 85 85
51 85 85 85
100 100 20 20
2. To formally force values of exactly zero to be blank (i.e.unplotted and thus leaving them the color of the plot background, no matter what palette is chosen or what the range of values is):
let vname_whitezero = if vname eq 0 then (-1.e34) else vname
shade/pal=any_palette vname_whitezero
or maybe leave near-zero values white:
let vname_whitenearzero = if abs(vname) lt 100 then (-1.e34) else vname
shade/pal=any_palette vname_whitenearzero
Billy K
On Nov 18, 2005, at 8:52 AM, James Booth wrote:
Is there a way to force the areas that have value zero to be colored in with white, when using the fill or shade command, regardless of the pallette I choose. Thanks. (I am using: FERRET v5.51) *_*_*_*_*_*_*_*_*_*_*_*_*_*_*_*_*_*_*_* Jimmy Booth Atmospheric Oceanography Graduate Student UW, JISAO, Seattle, WA~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ William S. Kessler NOAA / Pacific Marine Environmental Laboratory 7600 Sand Point Way NE Seattle WA 98115 USA william.s.kessler@noaa.gov Tel: 206-526-6221 Fax: 206-526-6744 Home page: http://www.pmel.noaa.gov/~kessler