Is this a bug in the interface description of v.mkgrid? It needs
grid=rows,columns but sets multiple=NO, so wxpython fails (needing two
values but getting one, but only providing an integer entry box).
Roger
--
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: [email protected]
---------- Forwarded message ----------
Date: Tue, 1 Sep 2009 14:40:13 +0200 (CEST)
From: Roger Bivand <[email protected]>
To: Alexandre VILLERS <[email protected]>
Cc: Aide R SIG GEO <[email protected]>
Subject: Re: [R-sig-Geo] GRASS commands
On Tue, 1 Sep 2009, Alexandre VILLERS wrote:
Goord morning,
I would like to use v.mkgrid (with spgrass6) and I need to specify box and
grid parameters, which both require 2 values box=5000,5000 grid=1000,1000
How do I specify this in my parameters list ?
parseGRASS6("v.mkgrid") returns
Command: v.mkgrid
Extension: .exe
Description: Creates a GRASS vector map of a user-defined grid.
Keywords: vector
Parameters:
name: map, type: string, required: yes, multiple: no
[Name for output vector map]
name: grid, type: integer, required: yes, multiple: no
[Number of rows and columns in grid]
name: position, type: string, required: no, multiple: no
[Where to place the grid]
name: coor, type: float, required: no, multiple: no
[Lower left easting and northing coordinates of map]
name: box, type: float, required: no, multiple: no
[Width and height of boxes in grid]
name: angle, type: float, required: no, multiple: no
[Angle of rotation (in degrees counter-clockwise)]
Flags:
name: q [Quiet; No chatter]
name: overwrite [Allow output files to overwrite existing files]
name: verbose [Verbose module output]
name: quiet [Quiet module output]
execGRASS("v.mkgrid", flags="overwrite",
parameters=list(map="grilleTest",
grid=c(as.integer(100),as.integer(100)), box=c(5000, 5000),
position="region"))
returns
Erreur dans doGRASS(cmd, flags = flags, parameters = parameters) :
Parameter <grid> has multiple values
How do I specify the two values when multiple is not allowed. I did not get
it....
Consider the statsgrass list for use of the interface between R and GRASS, in
this case there is an interaction between a possible bug in v.mkgrid and the
parsing of its parameters.
Since v.mkgrid does declare that grid does *not* take multiple values, the
(current) logic of doGRASS() is defeated, as it checks that the multiple
attribute if the GRASS parameter is not "NO", see
http://trac.osgeo.org/grass/browser/grass/trunk/vector/v.mkgrid/main.c#L74
The discrepancy between the code and the documentation is obvious.
Please ask on a GRASS list whether other scripted interfaces experience the
same problem - as far as I can see from the wxpython interface, only a single
value is accepted, but running the command fails because two are required (same
problem in reverse). Thw widget used for entering the parameter values does not
the entry of two values. The work-around for now is to use v.mkgrid in system()
directly.
Hope this helps,
Roger
Thanks
--
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: [email protected]
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