[GRASS-dev] Re: [GRASS GIS] #73: r.out.gdal tiff output does not work

Glynn Clements glynn at gclements.plus.com
Wed Apr 15 16:10:31 EDT 2009

Dylan Beaudette wrote:

> 3. Allow the user to specify what they would like NULL cells encoded as. 
> Unless I am overlooking something, it would seem reasonable to export a CELL 
> map to a signed integer format, and use some obvious negative value for NULL:

If you're exporting to a 32-bit (signed or unsigned) integer format,
the obvious choice for null is 0x80000000. That's what GRASS uses
internally, so it can never occur as a legitimate value (if a
computation ends up producing that value, it will get treated as a
null in all regards).

Glynn Clements <glynn at gclements.plus.com>

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