[GRASS-dev] How to calculate log() in v.db.update with SQLite backend?

[Markus Neteler]

Hi,

On Thu, Nov 20, 2014 at 10:53 AM, Markus Neteler <neteler at osgeo.org> wrote:
...
> Trying with my locally modified  v.db.update
>
> GRASS 7.1.svn (nc_spm_08_grass7):~ > g.copy
> vect=precip_30ynormals,myprecip_30ynormals
>
> GRASS 7.1.svn (nc_spm_08_grass7):~ > v.db.addcolumn
> myprecip_30ynormals column="logjuly double precision"
>
> GRASS 7.1.svn (nc_spm_08_grass7):~ > v.db.update myprecip_30ynormals
> column="logjuly" qcolumn="log(jul)"
> sqliteextra=/home/neteler/software/sqlite_extensions/libsqlitefunctions.so
>
> GRASS 7.1.svn (nc_spm_08_grass7):~ > v.db.select myprecip_30ynormals
> columns=jul,logjuly
> jul|logjuly
> 132.842|4.88916045210132
> 127|4.84418708645859
> 124.206|4.82194147751127
> 104.648|4.65060233738593
> 98.298|4.58800368106618
> ...
>
> Works.

Submitted to trunk in r63238. Please test (tomorrow) also on Windows
if possible (the name will be something like libsqlitefunctions.dll
which you need to provide to v.db.select).

Markus