[GRASSLIST:5738] Re: Creating DTM from shapefiles

[Michael Barton]

We just tested v.append with a set of vector files derived from DGN CAD
maps, imported into a UTM region with a WGS84 datum. It worked just fine,
combining both the vectors and attribute tables as I hoped. It (ogr2ogr that
is) automatically renamed the cat field to cat_ because, as Moritz notes, it
automatically creates a sequential cat value for the new vector file.

I am attaching a new version that is somewhat improved and more secure
(using g.tempfile) following advice from Hamish. I'll put this up on my
website. If people like it and it continues to work well, I can do a doc
page and add it to the CVS scripts too.

Michael


______________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ  85287-2402
USA

voice: 480-965-6262; fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton


> From: M?ris Nartišs <maris.nartiss at gmail.com>
> Date: Thu, 10 Feb 2005 15:58:18 +0200
> To: <mlennert at club.worldonline.be>
> Cc: <grasslist at baylor.edu>
> Subject: [GRASSLIST:5713] Re: Creating DTM from shapefiles
> 
> Hi,
> 
> thanks. I renamed vect1 cat column to cat1. Then reconnectd db usin
> cat1 as category. Then I used v.append and got good results: one
> vector data set with single db. This db now contains columns cat, cat1
> and augst. cat = cat1 for points from vect1 data;  cat1 = 0 and with
> new cat vaules for data from vect2. Most important - data in augst is
> for all records. Now I can delete unnecesary cat1 and will got 2
> merged vector data sets :)
> 
> Actualy I cant fuly understand how I got results, but I have them :)
> Some more easy way for all grass users would be nice (developers - you
> read this?).
> 
> 
> TNX all,
> Maris
> 
> On Thu, 10 Feb 2005 13:18:03 +0100 (CET), Moritz Lennert
> <mlennert at club.worldonline.be> wrote:
>> It seems to try to create a table containing all columns from the original
>> two
>> tables. Try renaming the columns of one of the tables to CAT2 and AUGST2 and
>> see what happens.
> 
>> If the above suggestion works, you could then use simple SQL to populate one
>> CAT column with unique cat nums.
>> 
>> Moritz
>> 
>> 

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