On Fri, 29 Jan 2010, Rainer M Krug wrote:
On Fri, Jan 29, 2010 at 2:32 PM, Roger Bivand <roger.biv...@nhh.no> wrote:
On Fri, 29 Jan 2010, Rainer M Krug wrote:
Hi
I have a question concerning readRAST6 and the plugin. When I use the
default (plugin=NULL), I get the error below,
Well, this does happen. I never knowingly use the plugins for raster or
vector any more, because I have multiple GDAL and GRASS installations, and
the cross-dependencies take more time to manage than any accruing benefit.
Use plugin=TRUE to avoid the sanity check.
If you would like to find the cause, please run debug(readRAST6) first,
then run the command, and print out the values of gg (returned by gmeta6()),
and fninfo (returned by GDALinfo). The values of gg$n and fninfo[5] are
found to differ, but gg$w and fninfo[4] not. It could be that fninfo[5] is
set wrongly; in GDALinfo, it is:
ysign <- sign(gt[6])
offset.y <- ifelse(ysign < 0, gt[4] + ysign * d[1] *
abs(cellsize[2]), gt[4] + abs(cellsize[2]))
where gt is the vector of values returned by RGDAL_GetGeoTransform from the
file-specific driver, and d[1] is the number of rows.
If you in addition say debug(GDALinfo), and print the values of gt, we
could see whether the values seem sane for this driver. They "must" be
anyway for reading with plugin=TRUE to work, because they set up the
GridTopology for the object read in; checking with gdalinfo of the same
raster would also be helpful.
Short answer, use plugin=TRUE if you want to use it.
Thanks Roger - I'll probably do that.
But what are the advantages / disadvantages of using the plugin or not?
Because the data are read directly from the GRASS GISDBASE file into R
memory without the writing and reading of an intermediary GTiff/shapefile,
the plugin may be faster. From earlier discussions on the grass-stats
list, this is the usual justification.
Roger
Rainer
Hope this helps,
Roger
x <- readRAST6("MASK")
raster map/current region mismatch detected in components:
cols rows origin.northing origin.easting
TRUE TRUE FALSE TRUE
set plugin=TRUE to override; continuing with plugin=FALSE
I am absolutely sure, that the raster map:
execGRASS("r.info", parameters=list(map="MASK"))
+----------------------------------------------------------------------------+
| Layer: MASK Date: Fri Jan 29 13:19:03 2010
|
| Mapset: HLsim_Rtmpe2v0qc Login of Creator: rkrug
|
| Location: grass
|
| DataBase: /home/rkrug/Documents/Projects/HakeaLandscape/trunc/
|
| Title: Reclass of region in HLsim_Rtmpe2v0qc ( MASK )
|
| Timestamp: none
|
|----------------------------------------------------------------------------|
|
|
| Type of Map: reclass Number of Categories: 1
|
| Data Type: CELL
|
| Rows: 520
|
| Columns: 192
|
| Total Cells: 99840
|
| Projection: UTM (zone -34)
|
| N: 6247000 S: 6195000 Res: 100
|
| E: 270200 W: 251000 Res: 100
|
| Range of data: min = 1 max = 1
|
|
|
| Data Source:
|
| Reclassified map based on:
|
| Map [region] in mapset [HLsim_Rtmpe2v0qc]
|
|
|
| Data Description:
|
| generated by r.reclass
|
|
|
|
|
|----------------------------------------------------------------------------|
| Reclassification of [region] in mapset [HLsim_Rtmpe2v0qc]
|
|
|
| Category Original categories
|
|
|
| 1 1
|
+----------------------------------------------------------------------------+
execGRASS("g.region", flags="p")
projection: 1 (UTM)
zone: -34
datum: wgs84
ellipsoid: wgs84
north: 6247000
south: 6195000
west: 251000
east: 270200
nsres: 100
gdal info:
library(rgdal)
Loading required package: sp
Geospatial Data Abstraction Library extensions to R successfully loaded
Loaded GDAL runtime: GDAL 1.6.3, released 2009/11/19
Path to GDAL shared files: /usr/share/gdal16
Loaded PROJ.4 runtime: Rel. 4.7.1, 23 September 2009
Path to PROJ.4 shared files: (autodetected)
sessionInfo()
R version 2.10.1 (2009-12-14)
i486-pc-linux-gnu
locale:
[1] LC_CTYPE=en_ZA.UTF-8 LC_NUMERIC=C
[3] LC_TIME=en_ZA.UTF-8 LC_COLLATE=en_ZA.UTF-8
[5] LC_MONETARY=C LC_MESSAGES=en_ZA.UTF-8
[7] LC_PAPER=en_ZA.UTF-8 LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_ZA.UTF-8 LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] multicore_0.1-3 RSQLite_0.8-0 DBI_0.2-5 spgrass6_0.6-12
[5] XML_2.6-0 maptools_0.7-29 lattice_0.18-3 foreign_0.8-38
[9] simecol_0.6-9 deSolve_1.6 rgdal_0.6-24 sp_0.9-52
loaded via a namespace (and not attached):
[1] grid_2.10.1 tools_2.10.1
Cheers,
Rainer
--
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.biv...@nhh.no
--
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.biv...@nhh.no
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