[Gdal-dev] modis sinusoidal tiles: bug in gdal?

[Christopher Barker]

Vincent Schut wrote:
> - md says CHARACTERISTICBINSIZE=463.312716527778
> - (6371007.181 * 2pi) / 86400 = 463.31271656938469
> Now which one is non-accurate, their spheroid or their pixel size?

These are the same to single precision floating point -- was all 
storage/calculation done in doubles? I expect not. We all know that 
checking equality is problematic with floating point -- all you can do 
is check that they are the same to the precision expected, and this sure 
looks close to me.

looking closer, they are the same for the first 10 decimal digits, and 
your calculation is based on ten digits input.

-Chris





-- 
Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
NOAA/NOS/OR&R            (206) 526-6959   voice
7600 Sand Point Way NE   (206) 526-6329   fax
Seattle, WA  98115       (206) 526-6317   main reception

Chris.Barker at noaa.gov