Ops, you're right Bob. So the problem is the huge negative value... So the problem is how to substitute it, maybe with a more treatable value outside my raster range...
giovanni 2011/10/31 Moskovitz, Bob <[email protected]> > Hi Giovanni,**** > > ** ** > > I’ve seen -3.4028234663852886e+038 (which is a huge negative value. Your > minds eye probably saw a “-“ instead of “+”) as a nodata value.**** > > ** ** > > Regards,**** > > Bob**** > > ** ** > > Bob Moskovitz**** > > Seismic Hazards Mapping Program**** > > California Geological Survey**** > > ** ** > > CONFIDENTIALITY NOTICE: This communication is intended only for the use of > the individual or entity to which it is addressed. This message contains > information from the State of California, California Geological Survey, > which may be privileged, confidential and exempt from disclosure under > applicable law, including the Electronic Communications Privacy Act. If the > reader of this communication is not the intended recipient, you are hereby > notified that any dissemination, distribution, or copying of this > communication is strictly prohibited.**** > > ** ** > > ** ** > > ** ** > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *G. Allegri > *Sent:* Monday, October 31, 2011 11:19 AM > *To:* [email protected] > *Subject:* [gdal-dev] problems with calculations with very small numbers > (nearzero)**** > > ** ** > > Hi, **** > > I'm having some troubles with raster algebra on a raster with very small > (near zero, but not).**** > > I'm using numpy (through python gdal) to do a multiplication, eg > numpy.multiply(rasterarr,2), but I obtain the following raster stats: > http://pastebin.com/hHiUrWwD.**** > > ** ** > > I suppose that -3.4028234663852886e+038 values are causing the problems, > and I wonder wha'ts the best way to deal with these kind of values... Maybe > rounding them to zeros?**** > > I've tried to do it using the LUT tag inside a VRT dataset, but it doesn't > seem to do the job.**** > > ** ** > > giovanni**** >
_______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
