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From: charlie@wam.umd.edu (Charles William Fletcher)
Newsgroups: comp.sys.next
Subject: Re: NeXT Mathematica Bug
Message-ID: <1991Mar4.035543.19802@wam.umd.edu>
Date: 4 Mar 91 03:55:43 GMT
References: <1991Mar3.053006.2986@math.ucla.edu>
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In article <1991Mar3.053006.2986@math.ucla.edu> barry@pico.math.ucla.edu (Barry Merriman) 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).
>
>The bug: Tanh[x] is not computed correctly. To _see_ if you have
>it, do
>
>Plot[Tanh[x],{x,-3,3}]
>
>and see if there is an obvious discontinuity in the graph. Or,
>do
>
>Tanh[-1.8]
>
>and see if you get a number < -1 (note Range of tanh is (-1,1)).
>
>The consensus of the mathematica mailing list is that this bug is
>a byproduct of the interaction between M'ma 1.2 and NeXTStep 2.0
>(although one fellow claims the above crashes his SparcStation!?)
>Hopefully it will be fixed in M'ma 2.0---since Wolfram is on
>tour and will be at UCLA next week, I'll ask him :-).
>
>However, if you write your own tanh[x] in terms of exponentials,
>it works fine.
>
>--
>Barry Merriman
>UCLA Dept. of Math
>UCLA Inst. for Fusion and Plasma Research
>barry@math.ucla.edu (Internet)


Wolfram left a message on the math net that a minimal C program *compiled*
on an 040 NeXT returned an incorrect value for the TANH. His conclusion
is to blame the math (C) library on the NeXT which is used by Mma. Cameron
Smith (formally of WRI) concurs after running Mma several places.

Anyone out there want to try this and post results? Is this a NeXT bug or an
040 bug?

-Charlie