Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!hamblin.math.byu.edu!news From: smithw@hamblin.math.byu.edu (Dr. William V. Smith) Newsgroups: comp.sys.next Subject: Re: NeXT Mathematica Bug Message-ID: Date: 4 Mar 91 04:39:23 GMT References: <1991Mar3.053006.2986@math.ucla.edu> <1991Mar4.035543.19802@wam.umd.edu> Sender: news@hamblin.math.byu.edu (Usenet News) Distribution: na Organization: Brigham Young University Lines: 24 In-Reply-To: charlie@wam.umd.edu's message of 4 Mar 91 03:55:43 GMT In article <1991Mar3.053006.2986@math.ucla.edu> barry@pico.math.ucla.edu (BarryMerriman) writes: >I have found a nasty, basic bug in NeXT Mathematica >(Mathematica 1.2, running on a 2.0 Slab---but copied from >a 1.0a 030 cube, though). This bug is apparently not a MMA kernel bug. The function is correctly evaluated and plotted with an '030 NeXT MMA 1.2 (Jan. 1990 version), but the same version running on an '040 NeXTcube shows the problem (both cubes running 2.0 NeXT software(extended)). The '030 - 1.0a software does not seem to have this problem. So. . . This may be a hardware based (or perhaps hardware related) problem. It does not seem to show up on other MMA platforms (which also have their own bugs with regard to MMA graphics). Someone has also noted a problem with C and the hyperbolic tangent function ('040 NeXTs). It's quite possible these are the same difficulty. The problem goes away if instead of calling tanh, you use the explicit definition of tanh in terms of the exponential function, so this may be a problem with the 68040 itself. The rather interesting thing is that the problem only seems to manifest itself over a rather narrow range of negative values (apparently) as doing Plot[Tanh[x], {x,-3,3}] shows. I might note in the same vein that tan also seems to have some plot problems in MMA over certain ranges (maybe it was arctan- can't remember now) on the NeXT, but I have not tried to duplicate these on other platforms or other NeXT configs. -Bill -- EMail: smithw@hamblin.math.byu.edu or uunet!hamblin.math.byu.edu!smithw SMail: Math Dept. -- 314 TMCB; BYU; Provo, UT 84602 (USA) NeXTmail: smithw@mathnx.math.byu.edu Phone: +1 801 378 2061 FAX: +1 801 378 2800