[GRASS-user] Bug or feature? v.net.alloc

[Christian Braun]

So, it is a feature of v.net.alloc that v.db.addtable isn't done  
automatically for resulting data set?

cheers
Christian

On 06.10.2009, at 12:28, achim wrote:

> Hi,
>
> there are three levels you have to think of:
> first level: geometry; every geometry element has an id number
> second level: category; category numbers can point to one or many
> geometry ids
> third level: database; in tables feature information is stored; every
> geometry(group) with a category can be addressed by the same (unique)
> numbers in a table with column 'cat'
>
> Its not enough just to make new categories. You have to create the  
> table
> with:
>
> db.droptable -f table=yourtable ##if already one exists
>
> v.db.connect -d map=yourtablesmap ##if you want to delete old  
> connections
>
> v.db.addtable map=yourtablesmap ##automatically columns="cat INTEGER"
> will be ran and each category of the map gets an entry; default is
> layer=1, so categories for layer one will be made; the tables name  
> will
> be "yourtablesmap"; for layer=2 "yourtablesmap_2"...
>
> Greets,
> Achim
>
>
>
> PS:
> little script to renew categories
>
> --%<--
>
> ## INPUT:
> ##  $1 vector map with changed features
> ##  $2 layer of changed features
> ##  $3 type of features to change (line,point,boundary,...)
> ################################################
>
> v.category input=$1       output=$1_nocat option=del  type=$3
> layer=$2 --o
> v.category input=$1_nocat output=$1                  type=$3 layer= 
> $2 --o
>
> --%<--
>
>
> Christian Braun schrieb:
>> Hi all,
>>
>> I am using v.net.alloc to create 'catchments' for traffic stations.
>> Working flawlessly so far...
>> I see categories with 'v.category resultmap option=report' and it
>> visualizes also the resultmap with categories.
>>
>> But if I do a v.info -c on the resultmap I get a warming that no DB
>> connection is defined. This is the part where I miss the 'new'
>> information. If I want to go on working with the newly defined
>> 'catchments' I have to export them as Shape or something else and
>> reimport it again to have the cats in the table.
>> Is this foreseen like that?
>>
>> cheers
>> Christian
>>
>> ------------------------------------------------------------
>> Dipl. Geogr. Christian Braun
>> Tel: +352- 425991-608
>> Mobil: +49-179-6845896
>> Mail: christian.braun at tudor.lu
>>
>> Resource Centre for Environmental Technologies,
>> Public Research Centre Henri Tudor,
>> Technoport Schlassgoart,
>> 66 rue de Luxembourg,
>> P.O. BOX 144,
>> L-4002 Esch-sur-Alzette, Luxembourg
>>
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