A curiosity: why the GDAL-Grass plugin is better then the built-in
GDAL support for Grass? I came to this question while I was choosing
wether to compile GDAL with or without Grass support and to use or not
the GDAL-Grass plugin...
Giovanni
On Tue, Jul 08, 2008 at 11:46:40PM +0200, we recorded a bogon-computron collision of the <giohappy@gmail.com> flavor, containing:
A curiosity: why the GDAL-Grass plugin is better then the built-in
GDAL support for Grass? I came to this question while I was choosing
wether to compile GDAL with or without Grass support and to use or not
the GDAL-Grass plugin...
Because building Grass support into GDAL requires that you:
1) Build GDAL without grass support
2) Build GRASS
3) Rebuild GDAL with grass support.
To build GDAL with GRASS support requires GRASS libraries to be built first,
but you can't build GRASS libraries without GDAL being installed first.
With the plugin, you only have to do the build of GDAL once:
1) Build GDAL without grass support
2) Build GRASS
3) Build the plugin.
The plugin isolates the GRASS support more appropriately, and avoids the
circular dependency.
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Thanks Tom.
Ok. I had already built Grass on GDAL from repo. Then I needed ecw
support so I built my own GDAL (it could see the already installed
Grass, so I've asked Grass support), and then I've built Grass against
my new GDAL...
So, the use of GDAL-Grass plugin is needed to avoid circular
dependency, but there aren't differences in funtionality, speed, etc.
Right?
Hi,
concerning just GRASS, GDAL with GRASS support has been required just
for old r.out.gdal script (now r.out.gdal.sh). Since this module is
now written in C (>=6.3), GDAL doesn't require GRASS support to run
r.out.gdal.
Martin
2008/7/9 G. Allegri <giohappy@gmail.com>:
Thanks Tom.
Ok. I had already built Grass on GDAL from repo. Then I needed ecw
support so I built my own GDAL (it could see the already installed
Grass, so I've asked Grass support), and then I've built Grass against
my new GDAL...So, the use of GDAL-Grass plugin is needed to avoid circular
dependency, but there aren't differences in funtionality, speed, etc.
Right?
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Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *
Does that mean that circular dependency has finally been dropped?
Unless one really needs r.out.gdal.sh?
How about OGR?
Ben
Martin Landa wrote:
Hi,
concerning just GRASS, GDAL with GRASS support has been required just
for old r.out.gdal script (now r.out.gdal.sh). Since this module is
now written in C (>=6.3), GDAL doesn't require GRASS support to run
r.out.gdal.Martin
2008/7/9 G. Allegri <giohappy@gmail.com>:
Thanks Tom.
Ok. I had already built Grass on GDAL from repo. Then I needed ecw
support so I built my own GDAL (it could see the already installed
Grass, so I've asked Grass support), and then I've built Grass against
my new GDAL...So, the use of GDAL-Grass plugin is needed to avoid circular
dependency, but there aren't differences in funtionality, speed, etc.
Right?
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grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user
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Hi,
2008/7/9 Benjamin Ducke <benjamin.ducke@oxfordarch.co.uk>:
Does that mean that circular dependency has finally been dropped?
Unless one really needs r.out.gdal.sh?
yes, I would guess so (GRASS >= 6.3)
How about OGR?
Both the modules (v.in/out.ogr) are written in C. GDAL with GRASS
support not needed here.
Martin
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Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *
On Wed, 9 Jul 2008, Benjamin Ducke wrote:
Does that mean that circular dependency has finally been dropped?
Unless one really needs r.out.gdal.sh?
Well, you might want GDAL to be able to read GRASS datasets outside GRASS for other purposes - this was possible long before r.out.gdal.sh came into being and is the primary purpose of the GRASS support in GDAL as far as I understand it.
But as Martin said speaking from a GRASS point of view, GRASS does not need GDAL to be compiled with GRASS support or to have a GDAL-GRASS plugin enabled.
Paul
Martin, Paul:
Terrific.
Thanks for the update.
Ben
Martin Landa wrote:
Hi,
2008/7/9 Benjamin Ducke <benjamin.ducke@oxfordarch.co.uk>:
Does that mean that circular dependency has finally been dropped?
Unless one really needs r.out.gdal.sh?yes, I would guess so (GRASS >= 6.3)
How about OGR?
Both the modules (v.in/out.ogr) are written in C. GDAL with GRASS
support not needed here.Martin
--
Benjamin Ducke
Senior Applications Support and Development Officer
Oxford Archaeological Unit Limited
Janus House
Osney Mead
OX2 0ES
Oxford, U.K.
Tel: +44 (0)1865 263 800 (switchboard)
Tel: +44 (0)1865 980 758 (direct)
Fax :+44 (0)1865 793 496
benjamin.ducke@oxfordarch.co.uk
------
Files attached to this email may be in ISO 26300 format (OASIS Open Document Format). If you have difficulty opening them, please visit http://iso26300.info for more information.
On Wed, Jul 9, 2008 at 1:04 PM, Paul Kelly
<paul-grass@stjohnspoint.co.uk> wrote:
On Wed, 9 Jul 2008, Benjamin Ducke wrote:
Does that mean that circular dependency has finally been dropped?
yes, for years now 
Unless one really needs r.out.gdal.sh?
Well, you might want GDAL to be able to read GRASS datasets outside GRASS
for other purposes
right, for example with Mapserver. See
http://grass.itc.it/start.html
for some examples (the first is broken apparently, the others work).
But as Martin said speaking from a GRASS point of view, GRASS does not need
GDAL to be compiled with GRASS support or to have a GDAL-GRASS plugin
enabled.
Likewise from the GDAL point of view.
Markus
Markus Neteler pisze:
On Wed, Jul 9, 2008 at 1:04 PM, Paul Kelly <paul-grass@stjohnspoint.co.uk> wrote:
On Wed, 9 Jul 2008, Benjamin Ducke wrote:
Unless one really needs r.out.gdal.sh?
Well, you might want GDAL to be able to read GRASS datasets outside
GRASS for other purposes
right, for example with Mapserver. See http://grass.itc.it/start.html
for some examples (the first is broken apparently, the others work).
Or for QGIS to be able to read GRASS rasters (GRASS vectors it supports
natively I guess).
Maciek
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