I went to convert my _FillValue to NAN; I found that upon reading data
and doing comparisons a false is always returned:
if (datum[i] == vp->attr->missingValue) // is always false if nan's
At first I thought I was back in the world of round off hell until I was
pointed to:
http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
specifically these lines:
"A NAN will never return true on a <= comparison," and
"One other complication is that comparisons involving NANs are always
supposed to return false, "
I would like to suggest that mention of this be made on the netCDF Best
Practices page where you point people to use NAN as the _FillValue.
...then I'd like to whine that I have to retro-fit all my code and
double the number of checks for every data point to determine if it's
_Fill/missing (...using isnan(3)). :)
--Chris
