id summary reporter owner description type status priority milestone component version severity resolution keywords cc 4484 gdalwarp on large netcdf datasets sets data from first input dataset to and generates error if -dstnodata option is used with netcdf-4 file hsumanto etourigny "Was trying to combine 2 large netcdf tiles into a single tile using gdalwarp and found a few interesting issues below: The two large netcdf tiles could found here:[[BR]] http://staff.vpac.org/~hsumanto/tile_x0_y0.nc http://staff.vpac.org/~hsumanto/tile_x1_y0.nc '''gdalwarp into nc4c with -dstnodata option:'''[[BR]] Error encountered and output dataset viewed in QGIS is '''NOT OK''' {{{ gdalwarp -tr 500.0 500.0 -t_srs EPSG:3112 -te -2576984.0 -5211665.0 1992016.0 -1219665.0 -r near -dstnodata 9.969209968386869E36 -of netCDF -co COMPRESS=DEFLATE -co ZLEVEL=6 -co FORMAT=NC4C -co WRITE_GDAL_TAGS=yes tile_x0_y0.nc tile_x1_y0.nc tile_combined-nc4c.nc Creating output file that is 9138P x 7984L. Processing input file tile_x0_y0.nc. Using internal nodata values (eg. 9.96921e+36) for image tile_x0_y0.nc. 0...10...20...30...40...50...60...70...80...90...100 - done. Processing input file tile_x1_y0.nc. Using internal nodata values (eg. 9.96921e+36) for image tile_x1_y0.nc. ERROR 1: netcdf error #-122 : NetCDF: Attempt to define fill value when data already exists. . at (netcdfdataset.cpp,SetNoDataValue,750) 0...10...20...30...40...50...60...70...80...90...100 - done. }}} '''gdalwarp into nc4c without -dstnodata option:'''[[BR]] No error but output file when viewed in QGIS is '''NOT OK''' {{{ gdalwarp -tr 500.0 500.0 -t_srs EPSG:3112 -te -2576984.0 -5211665.0 1992016.0 -1219665.0 -r near -of netCDF -co COMPRESS=DEFLATE -co ZLEVEL=6 -co FORMAT=NC4C -co WRITE_GDAL_TAGS=yes tile_x0_y0.nc tile_x1_y0.nc tile_combined-nc4c_withnodstnodata.nc }}} '''gdalwarp into geotiff:'''[[BR]] No error and output file when viewed in QGIS is '''OK''' {{{ gdalwarp -tr 500.0 500.0 -t_srs EPSG:3112 -te -2576984.0 -5211665.0 1992016.0 -1219665.0 -r near -dstnodata 9.969209968386869E36 tile_x0_y0.nc tile_x1_y0.nc tile_combined-tif.tif }}} Note: To view nc4c files with QGIS, you might have to convert nc4c into geotiff using gdal_translate as QGIS currently can not open nc4c files directly. The QGIS screenshots are attached as well. " defect closed normal closed_because_of_github_migration default unspecified normal wontfix netcdf etourigny terryrankine Even Rouault