Does Python have a long floating data type please?
Tim Peters
tim_one at email.msn.com
Sat Apr 1 00:29:05 EST 2000
[David C. Ullrich, notes some examples of dubious intervals computed
by Jurjen N.E. Bos's real.py module]
Yes, and I've posted others in the past (including cases that aren't near
0).
Jurjen used a very clever storage-efficient representation, but didn't
record correspondingly clever correctness arguments <wink>. Sometimes it's
easy to see a bug, sometimes I have no idea what he was thinking.
This isn't unusual for these kinds of pkgs, though! Correctness proofs can
be quite involved. Valérie Ménissier-Morain has submitted a 59-page article
giving correctness proofs for her version of this quest, available somewhere
more-or-less obvious under
http://pauillac.inria.fr/~menissier/
> ... - at this point I decided to give up on real.py and make my own.
Which is why there are a dozen packages like this out in the world each with
its own set of unique subtle bugs <wink>. Since this stuff runs too slow to
use for truly large problems anyway, I never understood why pkgs try to
conserve storage at the cost of vastly subtler reasoning. Guess it's seen
as a challenge.
personally-more-excited-by-things-that-are-obviously-right-than-by-
things-that-aren't-obviously-wrong-ly y'rs - tim
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