Markus Metz wrote:
> > - all floating point: IEEE's NaN
>
> Problem with NaN? According to IEEE 754, x == y is always FALSE if
> either x or y or both are NaN. Assuming (nodata =
> GDALGetRasterNoDataValue()) == NaN, then going through all cells if
> (cell == nodata) will always be FALSE, nodata cells may not be detected?
> Depends on each implementation of nodata detection? Can be solved for
> GRASS, but how is this done in all other GIS applications?
if (x == nodata || isnan(nodata) && isnan(x))
isnan() is C99 and POSIX, or it can be defined as e.g.:
#define ISNAN(x) ((x) != (x))
--
Glynn Clements <gl...@gclements.plus.com>
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