[gdal-dev] Numeric accuracy

[Ari Jolma]

I have been bitten twice, once with ArcGIS and now with Rasdaman WCS, 
with numeric accuracy.

I'm making a data request on the corner of the bounding box, let's say 
it has minimum X of 75042.7273594. I'm setting my minX to that value and 
I'm enforcing it to that value with MAX (this was introduced because of 
a case with ArcGIS). The I print that to the request with "%.18g" (it 
was "%.15g" earlier but I changes it to that because of ArcGIS) and the 
result is 75042.7273593999998, which is not good for Rasdaman, since it 
is formally less than 75042.7273594. Although, in gdb

(gdb) p 75042.7273594 > 75042.727359399999
$7 = false

Any ideas how to detect/prevent these kinds of situations? Keep the 
checks and go back to "%.15g"? Not ok with ArcGIS.

Ari