[GRASS5] Re: r.in.gdal - precision problem in lib/gis/adj_cellhd.c

[Markus Neteler]

As a followup:

Hacking lib/gis/adj_cellhd.c to permit the import, 
I get the following cell header:

grassdata/latlong/PERMANENT/cellhd/srtm90_gtopo30
proj:       3
zone:       0
north:      90:00:00.000001N
south:      39:59:59.990613N
east:       20:00:00.007509E
west:       20:00:00.000001W
cols:       4800
rows:       6000
e-w resol:  0:00:30.000002
n-s resol:  0:00:30.000002
format:     -1
compressed: 2

Probably it's a GRASS/GDAL issue with LatLong data?

Fixing the cell header files manually solved the
problem but isn't very elegant.

Any hints are welcome

 Markus 

On Wed, Apr 06, 2005 at 03:23:00PM +0200, Markus Neteler wrote:
> Hi,
> 
> I tried to import the Europe tile of SRTM/GTOPO30 from GLCF.
> There is a small issue which makes GRASS refuse the file:
> 
> gdalinfo SRTM_GTOPO_u30_n090w020.tif
> Driver: GTiff/GeoTIFF
> Size is 4800, 6000
> Coordinate System is:
> GEOGCS["WGS 84",
>     DATUM["WGS_1984",
>         SPHEROID["WGS 84",6378137,298.2572235629972,
>             AUTHORITY["EPSG","7030"]],
>         AUTHORITY["EPSG","6326"]],
>     PRIMEM["Greenwich",0],
>     UNIT["metre",1],
>     AUTHORITY["EPSG","4326"]]
> Origin = (-20.000000,90.000000)
> Pixel Size = (0.00833333,-0.00833333)
> Metadata:
>   TIFFTAG_DOCUMENTNAME=D:\Kuan\srtm\SRTM30\w020n90_new.tif
>   TIFFTAG_IMAGEDESCRIPTION=IDL TIFF file
>   TIFFTAG_XRESOLUTION=100
>   TIFFTAG_YRESOLUTION=100
>   TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Corner Coordinates:
> Upper Left  ( -20.0000000,  90.0000000) ( 20d 0'0.00"W, 90d 0'0.00"N)
> Lower Left  ( -20.0000000,  39.9999974) ( 20d 0'0.00"W, 39d59'59.99"N)
> Upper Right (  20.0000021,  90.0000000) ( 20d 0'0.01"E, 90d 0'0.00"N)
> Lower Right (  20.0000021,  39.9999974) ( 20d 0'0.01"E, 39d59'59.99"N)
> Center      (   0.0000010,  64.9999987) (  0d 0'0.00"E, 65d 0'0.00"N)
> Band 1 Block=4800x1 Type=Float32, ColorInterp=Gray
> 
> -> looks reasonable
> 
> 
> GRASS 6.1.cvs (latlong):~ > r.in.gdal SRTM_GTOPO_u30_n090w020.tif out=srtm90_gtopo30
> A datum name wgs84 (WGS_1984) was specified without transformation parameters.
> Note that the GRASS default for wgs84 is towgs84=0.000,0.000,0.000.
> Projection of input dataset and current location appear to match.
> Proceeding with import...
> D0/0: North: 90.000000
> WARNING: G_set_window(): Illegal latitude for North
> 
> -> I have added debug output to lib/gis/adj_cellhd.c
> --> strange, but (using %.10f output):
> 
> GRASS 6.1.cvs (latlong):~ > r.in.gdal SRTM_GTOPO_u30_n090w020.tif out=srtm90_gtopo30
> A datum name wgs84 (WGS_1984) was specified without transformation parameters.
> Note that the GRASS default for wgs84 is towgs84=0.000,0.000,0.000.
> Projection of input dataset and current location appear to match.
> Proceeding with import...
> D0/0: North: 90.0000000002
> WARNING: G_set_window(): Illegal latitude for North
> 
> -> to me it looks like a C problem.
> 
> How can I convince lib/gis/adj_cellhd.c to work as desired?
> The comparison is currently:
> 
>  if (cellhd->north > 90.0)
>      return (_("Illegal latitude for North"));
> 
> Thanks,
>  Markus
>