[GRASS-user] ps.map rotation of symbols based upon DB column

[Hamish]

> Willem van Mierlo wrote:
> > I would like to make a geological map, with strike-dip symbols 
> > (orientation of planes). I was wondering whether is was possible to 
> > rotate point symbols (using vpoints) based upon a db-column (like the 
> > size - sizecol option for vpoints), since a map generally contains a lot 
> > of strike-dip symbols and entering every position and orientation of 
> > each symbol by hand is rather tedious?

Hamish wrote:
> It's a nice idea, give me a few minutes....

done in 6.3cvs: ps.map's vpoints instruction now has a rotatecolumn
option which works like rgbcolumn and sizecolumn. Rotation is measured in
degrees CCW. Screenshot attached (using as rotation val v.mkgrid cat*5).

It should work for EPS symbols/patterns as well:
  http://grass.gdf-hannover.de/wiki/AreaFillPatterns

New and only lightly tested, so I may have broken something. Note you can
use rotatecolumn, rgbcolumn, and sizecolumn all at the same time, maybe
to do some interesting multivariate thematic vector mapping.

I'd be interested in seeing how your strike-dip map comes out.

One thing I notice is that we may want an arrow symbol with a slightly
longer tail to it. see what I mean:
  http://grass.gdf-hannover.de/wiki/IconSymbols#Existing_symbols
or just modify arrow1,arrow2?


enjoy,
Hamish
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