[GRASSLIST:877] Re: GMT / GRASS use / shp2gmt

[Dylan Beaudette]

Allan,

Great! This is certainly a step in the right direction.

Just for the record, to compile this new version of shp2gmt.c I added the 
following to the makefile in the shputils dir:

shp2gmt_new:	shp2gmt_new.c shpopen.o dbfopen.o
	$(CC) $(CFLAGS) shp2gmt_new.c shpopen.o dbfopen.o $(LINKOPT) -o shp2gmt_new

where shp2gmt_new.c is the code you referenced.

works like a charm!

Cheers,

Dylan

On Tuesday 25 April 2006 04:14 pm, Allan Hollander wrote:
> Trevor,
>
> I'm a rank beginner at GMT but in my one exercise to date with it I
> learned the following. Mark Fenbers has modified the shp2gmt.c file to
> include the attribute info from the dbf file into the multi-segment
> separator of the psxy input file. His code is given in his message here:
> http://www.mechanik.tu-darmstadt.de/GMT-Help/Archiv/11021.html.
>
> The output from his shp2gmt version looks like this for a tiny extract
>
> from a state map of the US:
> >       Polygon #0      nVertices=17    nParts=1        cat=2   AREA=0 
> > PERIMETER=0.224 STATESP020=3    STATE="Alaska"  STATE_FIPS="02"
>
> -2.86129e+06    6.01613e+06
> -2.86152e+06    6.01607e+06
> -2.86163e+06    6.01615e+06
> -2.86178e+06    6.01631e+06
> -2.86248e+06    6.01724e+06
> -2.86327e+06    6.01807e+06
> etc.
>
> What I can then do is write an awk script to substitute in the correct
> -G and -W plotting parameters depending on the attributes. For instance
> running this bit of awk over the above input file
>
> {if ($0 ~ /Alaska/) printf "> -G175 -Wblack\n";
> else print;}
>
> should transform it into an input file where Alaska is plotted with a grey
> fill. With more complicated lookups in the awk script, one can do pretty
> sophisticated thematic mapping using this approach.
>
> Best wishes,
>
> Allan Hollander
>
> ---
>
> On Tue, 25 Apr 2006, Trevor Wiens wrote:
> > Grudgingly I'm using GMT after working through Dylan's example and am
> > getting it to be somewhat functional.
> >
> > I will be needing to script the building of a large number of maps
> > which I may store either in PostGIS or GRASS.
> >
> > I've noticed in the use of shp2gmt that there is no way of adding in a
> > z attribute for use with the thematic colour assignment feature in GMT.
> > If necessary I can extract bits based on different attributes and add
> > them in separately, but it would be nice to be able to simply define a
> > colour them once and be done with it. Any suggestions on how I can turn
> > an attribute column in GRASS into a z-element that will be converted
> > with shp2gmt would be appreciated.
> >
> > T

-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341