From octave-sources-request at bevo dot che dot wisc dot edu Mon Jul 24 16:15:45 2000 Subject: Re: Patch for nan/inf support without HAVE_*... From: Edward Jason Riedy To: "John W. Eaton" cc: octave-sources at bevo dot che dot wisc dot edu Date: Mon, 24 Jul 2000 14:15:42 -0700 And "John W. Eaton" writes: - - Can you explain what problem your patch is trying to solve? 1) Correctness. NaNs and Infs can still occur even when Octave's configuration process decides that xisnan and relatives should always return false. External libraries like LAPACK will certainly generate them. 2) Completeness. NaNs and +/-Inf are essential for a complete algebra. I haven't checked +/-0 consistency or how -Inf is handled yet. 3) Killing off #ifdef tests. The HAVE_ISNAN, etc. aren't necessary in most places. This came up during a discussion of NaNs, etc. in comp.lang.python. The question of how Octave handles them was raised, so I checked the code and found that it doesn't. Figured I'd at least pass along a patch rather than silently griping. There may well be problems with the patch, but I don't have access to hardware lousy enough for me to test it thoroughly. Someone with a VAX or IBM 370 might find a defect, although I believe everything should pass through cleanly. I don't know their behavior on overflow, so that may be a problem. Jason ----------------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.che.wisc.edu/octave/octave.html How to fund new projects: http://www.che.wisc.edu/octave/funding.html Subscription information: http://www.che.wisc.edu/octave/archive.html -----------------------------------------------------------------------