[GRASS-user] ascii files to import

[Kirk Wythers]

On Jul 31, 2007, at 9:47 AM, Michael Barton wrote:

> Kirk,
>
> Your method #1 is straightforward and should go fast. Do you need  
> all 100
> columns?

Thanks Michael. Yes, I am afraid that I need all 100, if only because  
I am not sure that I won't someday!

>
> A 3rd way is to make sure that the file has a column to serve as a
> "category/cat" field (integer), save it as a dbf file from Excel  
> and use
> v.in.db to create the points. This has the advantage that you can  
> name the
> fields more easily. You would then need to reproject it into UTM.

With this approach how would reproject to UTM? I assume you have read  
the dbf file into a lat lon location. Right? However, then I would  
need to move the data from the lat lon location to the UTM location.

>
> I'd be a little nervous about trying to convert from latlon to UTM  
> within a
> database. GRASS has routines specially designed to do accurate  
> reprojection.

This actually works pretty well using the PostGIS extensions on  
PostgrSQL (you can use db.connect to point grass to a pg database  
rather than the default dbf). There is a very useful tutorial written  
by Regina Obe´

http://www.bostongis.com/?content_name=postgis_tut03#30



>
> Michael
>
>
> On 7/30/07 1:59 PM, "Kirk Wythers" <kwythers at umn.edu> wrote:
>
> __________________________________________
> Michael Barton, Professor of Anthropology
> Director of Graduate Studies
> School of Human Evolution & Social Change
> Center for Social Dynamics & Complexity
> Arizona State University
>
> phone: 480-965-6213
> fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
>
>

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