[GRASS-user] ascii files to import

[Michael Barton]

Kirk,

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

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.

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.

Michael


On 7/30/07 1:59 PM, "Kirk Wythers" <kwythers at umn.edu> wrote:

> Greetings everyone,
> 
> I was just handed a 26,000 row by 100 column excel file which
> contains lat long coordinates of individual site locations. I need to
> project it onto a rater image (already in a grass utm location).
> 
> Two ideas come to mind... one is to read it into a grass lat long
> location with v.in.ascii and then reproject onto the utm location,
> the other is to read it into postgis and convert the lat long columns
> to meters, then import the postgis layer. Any suggestions as to
> advantages or disadvantages to either approach?
> 
> How do most of you handle these situations?
> 
> Best Regards,
> 
> Kirk
> 
> 
> Kirk R. Wythers, Research Fellow
> Dept. of Forest Resources
> University of Minnesota
> 1530 Cleveland Ave N
> Saint Paul, MN 55108
> tel: 612.625.2261
> email: kwythers at umn.edu
> 
> 
> 
> 
> 

__________________________________________
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