David, the issue was in the GXF driver that returns the nodata value as a double precision real, but the pixel data as single precision real. So when translating to AAIGrid, you can see the difference in precisions.
In trunk (r19868), I've made 2 changes : * cast nodata value to float to be consistant with precision of pixel data * add a GXF_DATATYPE configuration option that can be set to Float64 to get full precision for nodata value and pixel values. Best regards, Even Le Monday 14 June 2010 21:16:41 David Baker (Geoscience), vous avez écrit : > All, > > Using OpenEV from FWTools version 2.4.7 to convert the GXF file found at > http://pubs.usgs.gov/of/2000/ofr-00-0042/data/ from the GXF format to > AAIGrid format I have found an issue. In the GXF file the #DUMMY > value/string is -1e32 and this is the same value/string found in the data > portion of the GXF file. After conversion in the AAIGrid file, the NODATA > line reads > > NODATA_value -1.0000000000000001e+032 > > but the value -1.0000000331813535e+032 is found in the data portion of the > AAIGrid file where the value -1.0000000000000001e+032 should be found. As > OpenEV uses GDAL/OGR to do the conversion I have posted this issue here. > > Thanks, > > David M. Baker > Senior Geologist - Chief Technology Advisor > Chesapeake Energy Corporation > 405-935-3715 office > 405-496-5373 cell > [email protected]<mailto:[email protected]> > > > ________________________________ > This email (and attachments if any) is intended only for the use of the > individual or entity to which it is addressed, and may contain information > that is privileged, confidential and exempt from disclosure under > applicable law. If the reader of this email is not the intended recipient, > or the employee or agent responsible for delivering this message to the > intended recipient, you are hereby notified that any dissemination, > distribution or copying of this communication is strictly prohibited. If > you have received this communication in error, please notify the sender > immediately by return email and destroy all copies of the email (and > attachments if any). _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
