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Hello, There are several ways to control which color corresponds to which value of the data. First I will give a simple method, but it is not very flexible, and you will probably want to use the second idea. 1) Within one Ferret session or script, if you have issued a fill or shade command which automatically chooses levels on the palette, you can make more plots with the same levels by using the /LEVELS qualifier with no arguments. For example, yes? use coads_climatology yes? set view upper yes? shade/L=1 sst yes? set view lower yes? shade/levels/L=1/x=150:300/y=-40:40 sst Compare that with what happens in the second plot without the /LEVELS command. 2) You have even more control over the palettes if you use a palette which is defined by_value. In these kinds of palettes, the same value of the data field is always represented by the same color. You will need to create a custom palette for your particular kind of data, so that the values correspond to the range of values in that data. There is a discussion of the kinds of palettes and how to create them in the Users Guide, in the index under "palette, creation". You will want to study the second type that is listed in that section, palettes by_value. There is also a FAQ which shows examples of many of the palettes that are included with Ferret : How can I find a good color palette for my plot? at http://www.ferret.noaa.gov/Ferret/FAQ/graphics/colorpalettes.html and there is a demonstration script with Ferret, yes? go palette_demo The third example in this script shows plots using a by_value palette. Ansley Manke du hui wrote: Hi, I have a question. |