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

[Stuart Edwards]

sorry Marcus - forgot the list .....

On Feb 11, 2010, at 3:04 AM, Markus Neteler wrote:

> On Tue, Feb 9, 2010 at 3:40 PM, Stuart Edwards <sedwards2 at cinci.rr.com> wrote:
>> 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?
> 
> Create a .csvt file with the name of the .csv file (see manual of db.in.ogr).
> In this CSV-types file you can specify a type for each column.
> 
>> 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.
> 
> Perhaps it included white spaces?
> 
> Markus
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Thanks for the hint.  I wasn't familiar with the .csvt format.    I don't think there were any white spaces in my .csv files - e.g. '261,446,434,401,,346'   would indicate a missing value in the column between 401 and 346 - I also tried NULL and NA as options without success.

thanks again,

Stu