[GRASS-user] thematic vector map with non-numeric field values

[Hamish]

Tim Michelsen wrote:

> how do I disply a thematic map in GRASS for vector attributes that don't have
> numeric values?
> 
> I tried d.vect.thematic but it would only accept numeric values.
> 
> If I have a vector layer with all communities of a country and a attribute
> column with the community name and another column with the name of the
> corresponding federal state, how do I display for instance a thematic map
> with individual values based on the column with the sate names?

not very efficient, but you could use the d.vect where= column to restrict to
e.g. where="state = 'California'".  Perhaps write a script with v.db.select or
as Michael suggested add a GRASSRGB column and populate it with db.execute
WHERE state = '...'.   Another idea is to dissolve into states with d.dissolve
(by column), then randomly color states with d.vect -c.


Hamish



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