On Fri, 3 Apr 2009, Jarek Jasiewicz wrote:
> Hi
>
> I during batch processing of couple of maps I found strange behaviour of
> readRAST6 when I import cell map with value 999.
> Instead of 999 Na is imported (?? _
>
> It is for me completely strange, so I test it with folowing:
OK. This is a consequence of trying to guess the NODATA value to pass to
r.out.gdal, and I don't see it in 0.5-19 (my local slightly changed from
CRAN latest 0.5-18). For certain range values retrieved from r.info,
NODATA is assigned the value 999 (R/bin_link.R, about line 113). Please
try 0.5-18, I suspect that the condition was changed. Alternatively, set
NODATA to a suitable value outside the range of the data. Note that I
don't have a 6.5 GRASS, and if r.info output has changed format, the
parsing will be wrong, and
(!is.numeric(lres$min) || !is.finite(as.double(lres$min)) will be
triggered, setting NODATA to 999.
What does r.info test_map look like in 6.5? In 6.3 it is:
> system("r.info test_map")
+----------------------------------------------------------------------------+
| Layer: test_map Date: Fri Apr 3 08:41:58 2009 |
| Mapset: rsb Login of Creator: rsb |
| Location: spearfish60 |
| DataBase: /home/rsb/topics/grassdata |
| Title: ( test_map ) |
| Timestamp: none |
|----------------------------------------------------------------------------|
| |
| Type of Map: raster Number of Categories: 999 |
| Data Type: CELL |
| Rows: 143 |
| Columns: 190 |
| Total Cells: 27170 |
| Projection: UTM (zone 13) |
| N: 4928010 S: 4913700 Res: 100.06993007 |
| E: 609000 W: 589980 Res: 100.10526316 |
| Range of data: min = 999 max = 999 |
| |
| Data Description: |
| generated by r.mapcalc |
| |
| Comments: |
| 999 |
| |
+----------------------------------------------------------------------------+
I guess that there is a smarter way of getting the raster min/max too,
isn't there?
Hope this helps,
Roger
>
> echo "test_map=999"|r.mapclac
> R
> library(spgrass6)
> testNoPlugin=readRAST6("test_map",plugin=FALSE)
>
> summary(testNoPlugin@data)
>
> test Min. : NA 1st Qu.: NA Median : NA Mean : NaN 3rd
> Qu.: NA Max. : NA NA's :156740
>
> testPlugin=readRAST6("test_map",plugin=TRUE)
>
> summary(testPlugin@data)
>
> test Min. :999 1st Qu.:999 Median :999 Mean :999 3rd Qu.:999 Max.
> :999
>
> It is very strange for me but I tested it on several maps. I think someone
> could try to reproduce this.
>
> Jarek
>
>
> BTW:
>
> R version 2.8.1 (2008-12-22)
>
>
> library(spgrass6)
> Loading required package: sp
> Loading required package: rgdal
> Geospatial Data Abstraction Library extensions to R successfully loaded
> Loaded GDAL runtime: GDAL 1.5.3, released 2008/09/09
> GDAL_DATA: /usr/local/lib/R/site-library/rgdal/gdal
> Loaded PROJ.4 runtime: Rel. 4.6.1, 21 August 2008
> PROJ_LIB: /usr/local/lib/R/site-library/rgdal/proj
> GRASS GIS interface loaded with GRASS version: 6.5.svn
> and location: Rzeki
>
> Package: spgrass6
> Version: 0.5-16
> Date: 2008-11-13
> Built: R 2.8.1; ; 2009-01-02 14:02:31; unix
>
>
>
>
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--
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:
[hidden email]
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http://lists.osgeo.org/mailman/listinfo/grass-statsRoger Bivand
Economic Geography Section
Department of Economics
Norwegian School of Economics and Business Administration
Helleveien 30
N-5045 Bergen, Norway
