On 09.04.2005, at 01:04, Scott Gilbert wrote:
I think something we've been assuming is that the array data is basically IEEE-754 compliant (maybe it needs to be byteswapped). If that's not true, then we're going to need some new typecodes. We're not supporting the ability to pass VAX floating point around (Are we????).
This discussion has been coming up regularly for a few years. Until now the concensus has always been that Python should make no assumptions that go beyond what a C compiler can promise. Which means no assumptions about floating-point representation. Of course the computing world is changing, and IEEE format may well be ubiquitous by now. Vaxes must be in the museum by now. But how about mainframes? IBM mainframes didn't use IEEE when I used them (last time 15 years ago), and they are still around, possibly compatible to their ancestors. Another detail to consider is that although most machines use the IEEE representation, hardly any respects the IEEE rules for floating point operations in all detail. In particular, trusting that Inf and NaN will be treated as IEEE postulates is a risky business. Konrad. -- ------------------------------------------------------------------------ ------- Konrad Hinsen Laboratoire Leon Brillouin, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France Tel.: +33-1 69 08 79 25 Fax: +33-1 69 08 82 61 E-Mail: khinsen@cea.fr ------------------------------------------------------------------------ -------