> I noticed that you used both "nondeterministic" and > "reproducible" though.
LOL. The nondeterministic part is that the same calculation will give different answers and there doesn't appear to be a pattern to which of the several answers will occur. The reproducible part is that it happens from session-to-session > Are the specific values significant (e.g., do > you really need range(10000) to demonstrate the problem)? No, you just need to run the calculation several times at the command line: >>> -19400000000 * (1/100.0) -193994880.0 >>> -19400000000 * (1/100.0) -194000000.0 >>> -19400000000 * (1/100.0) -194000000.0 Raymond -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, October 19, 2006 1:44 PM To: Raymond Hettinger Cc: [email protected] Subject: Re: [Python-Dev] Nondeterministic long-to-float coercion Raymond> My colleague got an odd result today that is reproducible on Raymond> his build of Python (RedHat's distribution of Py2.4.2) but not Raymond> any other builds I've checked (including an Ubuntu Py2.4.2 Raymond> built with a later version of GCC). I hypothesized that this Raymond> was a bug in the underlying GCC libraries, but the magnitude of Raymond> the error is so large that that seems implausible. Does anyone Raymond> have a clue what is going-on? Not off the top of my head (but then I'm not a guts of the implementation or gcc whiz). I noticed that you used both "nondeterministic" and "reproducible" though. Does your colleague always get the same result? If you remove the set constructor do the oddball values always wind up in the same spots on repeated calls? Are the specific values significant (e.g., do you really need range(10000) to demonstrate the problem)? Also, I can never remember exactly, but are even-numbered minor numbers in GCC releases supposed to be development releases (or is that for the Linux kernel)? Just a few questions that come to mind. Skip _______________________________________________ Python-Dev mailing list [email protected] http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
