Helmut Kudrnovsky wrote: >>I am importing worldclim .asc files from the ipcc4 simulations >>(http://ccafs-climate.org/). These are latlong files with a global >>extent. I have compiled grass 6.4.2svn from source on ubuntu 11.10 and >>hope that I did everything correctly, according to the wiki. >> >>When importing, here is what I do and what happens: >> >>r.in.gdal -o input="/D/Documents/Spatial_Datasets/Climate/WorldClim/\ >>hccpr_hadcm3_a2a_2020s_prec_2_5min_asc/prec_10.asc" output="prec_10" > > tested here with > http://ccafs-climate.org/data/A2a_2020s/hccpr_hadcm3/hccpr_hadcm3_a2a_2020s_prec_2_5min_asc.zip > > gdalinfo hccpr_hadcm3_a2a_2020s_prec_2_5min.asc > > Driver: AAIGrid/Arc/Info ASCII Grid > Files: prec_10.asc > Size is 8640, 3600 > Coordinate System is `' > Origin = (-180.000000000000000,90.000000000119996) > Pixel Size = (0.041666666666700,-0.041666666666700) > Corner Coordinates: > Upper Left (-180.0000000, 90.0000000) > Lower Left (-180.0000000, -60.0000000) > Upper Right ( 180.0000000, 90.0000000) > Lower Right ( 180.0000000, -60.0000000) > Center ( 0.0000000, 15.0000000) > Band 1 Block=8640x1 Type=Int32, ColorInterp=Undefined > NoData Value=-9999 >
There is a tiny precision loss: Origin = (-180.000000000000000,90.000000000119996) Pixel Size = (0.041666666666700,-0.041666666666700) should be Origin = (-180.000000000000000,90.000000000000000) Pixel Size = (0.041666666666667,-0.041666666666667) pixel size is now as close as possible to 2.5 min. This is neither a gdal nor a grass bug, but a bug of the software used to produce these data. This can easily be fixed with e.g. gdal_translate -a_ullr -180 90 180 -60 prec_1.asc prec_1.tif then import the corrected tif. HTH, Markus M _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
