Hi devs,
Is it possible to extend the column option in v.reclass to accept more
than one column?
sometimes is really useful to reclass/dissolve using more columns and
also it is useful to keep more data in the attribute table.
If this make sense I will open a ticket
--
ciao
Luca
www.lucadelu.org
On 31/05/16 11:18, Luca Delucchi wrote:
Hi devs,
Is it possible to extend the column option in v.reclass to accept more
than one column?
But if you combine several columns, you would have to define rules. And this is exactly what the rules parameter is for which let's you define SQL-like rules combining as many columns as you want ?
> sometimes is really useful to reclass/dissolve using more columns and
> also it is useful to keep more data in the attribute table.
The problem is if you combine several features into one category, then which attributes should you keep ?
Moritz
On 31 May 2016 at 12:22, Moritz Lennert <mlennert@club.worldonline.be> wrote:
On 31/05/16 11:18, Luca Delucchi wrote:
Hi devs,
Is it possible to extend the column option in v.reclass to accept more
than one column?But if you combine several columns, you would have to define rules. And this
is exactly what the rules parameter is for which let's you define SQL-like
rules combining as many columns as you want ?
But I would like to use something like a GROUP BY statement, and I
don't know the values of cat in advance, should be this possible?
sometimes is really useful to reclass/dissolve using more columns and
also it is useful to keep more data in the attribute table.The problem is if you combine several features into one category, then which
attributes should you keep ?
I want to combine several features into one category only if the
attributes are the same, so it should keep all the attributes
Moritz
--
ciao
Luca
www.lucadelu.org
On 31/05/16 12:38, Luca Delucchi wrote:
On 31 May 2016 at 12:22, Moritz Lennert <mlennert@club.worldonline.be> wrote:
On 31/05/16 11:18, Luca Delucchi wrote:
Hi devs,
Is it possible to extend the column option in v.reclass to accept more
than one column?But if you combine several columns, you would have to define rules. And this
is exactly what the rules parameter is for which let's you define SQL-like
rules combining as many columns as you want ?But I would like to use something like a GROUP BY statement, and I
don't know the values of cat in advance, should be this possible?
I think that you will be better off creating a new column that you populate with new cat values using SQL and then use v.reclass using this.
sometimes is really useful to reclass/dissolve using more columns and
also it is useful to keep more data in the attribute table.The problem is if you combine several features into one category, then which
attributes should you keep ?I want to combine several features into one category only if the
attributes are the same, so it should keep all the attributes
You could identify the cat of the first line that has the attributes and attribute that cat to all the others with the same attributes.
Moritz