[GRASS-stats] Speedup of readVECT6() with plugin

[Roger Bivand]

On Mon, 23 Jun 2008, Roger Bivand wrote:

> I've submitted spgrass6_0.5-9.tar.gz to CRAN, so barring accidents it should 
> be out soon. If you're using the raster or vector plugins and have comments, 
> please let me know - look for the new plugin= argument, which is FALSE by 
> default to avoid problems, but can be NULL for autodetection, or TRUE to 
> force use if the plugin is known to be available.

My apologies, 0.5-9 was released on CRAN three weeks ago, so no change.

What I do need is advice on whether to leave plugin=FALSE, or to set 
plugin=NULL for autodetect, and risk foobars from existing user code 
assuming the current region rather than the raster region seen by the 
plugin if installed and autodetected.

My preference remains for plugin=FALSE, that is, users have to change to 
NULL or TRUE themselves, and accept the consequences of mixing up regions.

Is there a shell-level utility in GRASS to check whether the region of a 
raster is equal to the current working region - the function could call 
that and create a copy of the required raster in current resolution if 
they differ?

Roger

>
> Roger
>
> On Sun, 22 Jun 2008, Markus Neteler wrote:
>
>>  Dear Roger,
>>
>>  On Mon, Jun 2, 2008 at 10:03 AM, Roger Bivand <Roger.Bivand at nhh.no> wrote:
>> >  On Sun, 1 Jun 2008, Markus Neteler wrote:
>> > > > > > > >  On Sat, 31 May 2008, Markus Neteler wrote:
>> > > > > > > > >  I have to read in Lidar data from GRASS, so speed matters. 
>> > > > > > > > >  I have
>> > > > > > > > >  modified the readVECT6() function to not export to SHAPE 
>> > > > > > > > >  but
>> > > > > > > > >  read in directly via GRASS-GDAL/OGR plugin:
>>  ...
>> > >  thanks for the high speed rewrite of the interface. Downloaded and
>> > >  installed
>> > >  successfully (I see the new message
>> > >  "GRASS GIS interface loaded with GRASS version: 6.4.svn"
>> > > ) .
>> > > 
>> > > >  or a variant that works. The vector version looks OK,
>> > > 
>> 
>> >  Markus,
>> > 
>> >  For now, the plugin= argument defaults to FALSE. If NULL, it will
>> >  autodetect, if TRUE, it will try to use the plugin or fail. To avoid
>> >  breaking things for users with a plugin but scripts that might break, I 
>> >  set
>> >  plugin=FALSE for now. Once we have some experience, I'll increment the
>> >  version number from 0.5-* to 0.6-1, and set plugin=NULL by default.
>> > 
>>
>>  I have partially reinstalled R here. Should I continue to use the CVS
>>  version for this improvement? I feel that things won't be tested widely
>>  unless the code isn't easily available (i.e. CRAN).
>>
>>  Best wishes
>>  Markus
>> 
>
>

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no