[GRASS-user] Help using color tables (differences)

[Hamish]

Toms wrote:
> Thanks for your help! I had not played around much previously with
> color tables in GRASS, so your suggestions were very helpful.

it is a really nice & powerful system IMO.

> Attached is what I was after, in case you are interested.

I got it, but not sure if the list did due to the large size of the
attachment.

> We are beginning to run a distributed hydrologic model (U.S.
> NWS, RDHM) that can produce soil moisture estimates for 5 layers
> in depth. I'm showing the top 10-cm layer soil moisture. The modeling
> resolution is on a 4x4 km^2 grid, at hourly time steps. I was interested
> (initially) in producing soil moisture differences for the past day
> and past week.

nice.

just minor tips&tricks about the cartography-

- I'm not sure how you are making your PS -> PDF, but on the wiki you
will find how to do e.g. 300dpi instead of default 72pdi JPEGization.
(rather blurry at raster edges in top two frames for hardcopy)
http://grass.osgeo.org/wiki/Ps.map_scripts#Converting_PostScript_to_PDF

- I am not sure if it is appropriate for your map projection but also in
the wiki is tips to do nice rotated north arrows  (g.region -n)
http://grass.osgeo.org/wiki/Ps.map_scripts#Creating_a_fancy_North_Arrow
+ a bunch of north arrow "clipart"
http://grass.osgeo.org/wiki/IconSymbols#North_Arrows

- r.color's "bcyr" rule is the same as Matlab's default "Jet" rule. It's
actually a natural linear transition through the RGB 3D color-cube and
not any human artistic thing. (which is probably why it looks so good)
If you have matlab addicts in your office it will make them feel more at
home. Having said that, the top two panels look nice and dramatic already.

- if your rasters contain units meta-data (r.support) then the legends
will print a units label too. You can change the position of the label
but I think you might have to select switch that in the source code &
recompile.

- you can use the ps.map rectangle instruction to blank out lines behind
the legend (sorry SC).

- the ps.map legend instruction has a 'range' command so e.g. 1-day diff
legend can be even -0.15 to +0.15 instead of the default which stops at
the value of the what's actually in the map data.



Hamish