[GRASS-user] Re: v.rast.stats

Micha Silver Tue, 15 Jun 2010 02:09:52 -0700

Hello Sandile
(Please keep messages on the list- maybe others can help...)

On 15/06/2010 10:52, Sandile Gumede wrote:

Hi

Below is the output of r.info rainfall

Type of Map: raster               Number of Categories: 1020
    Data Type:    CELL
    Rows:         480
    Columns:      1440
    Total Cells: 691200
         Projection: Latitude-Longitude
             N: 33:40:46.49916S    S: 34:20:55.49928S   Res: 0:00:05.01875
             E: 19:10:16.50036E    W: 18:17:55.50036E   Res: 0:00:02.18125
    Range of data:    min = 0 max = 1020

The only unusual thing I notice above is that the resolution settings for the raster are different N-S and E-W. This came from the original tiff (see below) which also has rectangular pixels, and your use of the "-o" option when importing.
I wonder if that's what is causing your problems with v.rast.stats?? (the v.rast.stats module creates a temp raster at the *current region's resolution* settings, which might be different from this rainfall raster's rectangular resolution...)

Please give us the output of g.region -p.

Perhaps someone with more experience can answer: If v.rast.stats runs using a raster with resolution different from the current region settings what will happen?

Regards,
Micha

    Data Description:
     generated by r.in.gdal

    Comments:
     r.in.gdal -o -e input="/home/tgumede1/grassdata/TRMMLast03HRS.tif" output="rainfall" target="SRTMDEM"

And also the output of gdalinfo for the rainfall data:

Driver: GTiff/GeoTIFF
Files: TRMMLast03HRS.tif
Size is 1440, 480
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.2572235630016,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (18.298750099999999,-33.679583100000002)
Pixel Size = (0.000605902777778,-0.001394097291667)
Metadata:
AREA_OR_POINT=Area
TIFFTAG_DOCUMENTNAME=/TRMMRT/Pool/merged/gis/image/3B42RT.2010032900.03hr.tif
TIFFTAG_IMAGEDESCRIPTION=IDL TIFF file
TIFFTAG_SOFTWARE=IDL 6.1, Research Systems, Inc.
TIFFTAG_DATETIME=2010:03:29 04:53:11
TIFFTAG_XRESOLUTION=100
TIFFTAG_YRESOLUTION=100
TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
Image Structure Metadata:
COMPRESSION=LZW
INTERLEAVE=BAND
Corner Coordinates:
Upper Left ( 18.2987501, -33.6795831)
Lower Left ( 18.2987501, -34.3487498)
Upper Right ( 19.1712501, -33.6795831)
Lower Right ( 19.1712501, -34.3487498)
Center      ( 18.7350001, -34.0141665)
Band 1 Block=256x256 Type=UInt16, ColorInterp=Gray
2010/6/15 Micha Silver <mi...@arava.co.il>
On 15/06/2010 09:51, Sandile Gumede wrote:
if I run r.info -g rainfall, I get:

north=-33.679583
south=-34.34875
east=19.17125
west=18.29875

and if I run v.info -g catchments, I get:

north=-33.6795831
south=-34.3487498
east=19.1712501
west=18.2987501
top=0.000000
bottom=0.000000

OK, now we see that the regions are identical.
I'd like to see also the full output of
r.info rainfall
(it will give the max-min values of the raster) and also the output of
gdalinfo rainfall.tif (the original tiff file)
Perhaps then we can understand where the -NULL values are from?
2010/6/13 Micha Silver <mi...@arava.co.il>
(back on the ML)

Hi Sandile:
The error is popping up, apparently, because of the strange "-NULL" value. What is -NULL??
Can you display the rainfall raster? Does it look OK (some value everywhere?)

Perhaps run a check on the original rainfall.tif with gdalinfo to see what range of values it is showing? Then do r.info rainfall to show what range the GRASS raster has.

--
Micha

On 13/06/2010 12:13, Sandile Gumede wrote:

Hi,

Whats wrong with the rainfall data (rainfall.tif) if you get a DBMI-DBF driver error when running v.rast.stats vector=catchments raster=rainfall colprefix=precip?

SQL parser error: syntax error, unexpected NULL_VALUE processing 'NULL'
in statement:
UPDATE catchments SET precip_cf_=-NULL WHERE cat=2
Error in db_execute_immediate()

ERROR: Error while executing: 'UPDATE catchments SET precip_cf_=-NULL WHERE
cat=2'

This mail was received via Mail-SeCure System.
-- 
Micha Silver
http://www.surfaces.co.il/
Arava Development Co.  +972-52-3665918
    
--
Kind Regards
TS Gumede
CSIR, Meraka Institute
072 258 1650

This mail was received via Mail-SeCure System.
-- 
Micha Silver
http://www.surfaces.co.il/
Arava Development Co.  +972-52-3665918
    
--
Kind Regards
TS Gumede
CSIR, Meraka Institute
072 258 1650

This mail was received via Mail-SeCure System.

-- 
Micha Silver
http://www.surfaces.co.il/
Arava Development Co.  +972-52-3665918

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[GRASS-user] Re: v.rast.stats

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