[GRASS-user] how to change imported table column definitions - using 6.4 in Win XP

[Stuart Edwards]

On Feb 9, 2010, at 5:11 AM, Laszlo Nagy wrote:
> 
> (!) Have imported a csv to make a vector map.  All cols are listed as char. There are numeric columns (either two decimal values) that are listed as char. How can I change them to be numeric?

I had trouble with this recently - one cause of the problem in my case was the presence of data gaps -- any column with a data gap seemed to be imported as a 'char' column.  When I modified the table to eliminate missing data it worked fine.  

Also, by importing the csv table into an sqlite database, and using v.in.db, the results seem more predictable.  First you can review the real table properties better than with a simple csv table and second, it's then easier to edit out any problems or redefine columns.  The SQlite Database Browser is a good tool for this.

Stu
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