Re: A "singular" equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg14760] Re: A "singular" equation*From*: weber at math.uni-bonn.de (Matthias Weber)*Date*: Sat, 14 Nov 1998 03:07:52 -0500*Organization*: RHRZ - University of Bonn (Germany)*References*: <72bf2q$k3l@smc.vnet.net> <72e2ng$oi0@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <72e2ng$oi0 at smc.vnet.net>, "W. K. Bertram" <wkb at ansto.gov.au> wrote: > David Withoff wrote: > > > This worked ok for me. Check with Wolfram Research tech support. Maybe > > you have a corrupted/old/etc copy of Mathematica. > > > > % math > > Mathematica 3.0 for Solaris > > Copyright 1988-97 Wolfram Research, Inc. > > -- Terminal graphics initialized -- > > > > In[1]:= DSolve[(1-x^2)y'[x]^2==(1-y[x]^2),y[x],x] > > > > 2 2 2 2 > > x - Sqrt[-1 + x ] + x C[1] + Sqrt[-1 + x ] C[1] > > Out[1]= {{y[x] -> -------------------------------------------------}} > > 2 C[1] > > > > > > Dear David, > > I have exactly the same problem on my system as the previous writer. I'm > running Mathematica version 3.0.0 on a 200Mhz Pentium Pro under Windows > 95. When I try to execute the above command I get a "This program has > performed an illegal operation ..." message and the notebook freezes > up. Is this a feature of this particular verion of Mathematica? If so, > maybe Wolfram might consider offering its affected customers an upgrade > to a more recent version at a much better rate than the A$700 - A$800 > price that was quoted to me for an upgrade from version 3.0.0 to 3.0.1. > > Cheers, > Bill Bertram I agree with Bill. However, Mathematica 3.0.0 has quite a lot bugs like this (just browse through the newsgroup archives), and it if Wolfram would be willing to fix them all for free, this would keep them busy for years without payment... We all are interested in a stable and reliable symbolic and numeric ("integrated " ?) tool, and I would appreciate if Wolfram would accept more feedback from customers. I spent a lot of time locating reproducible bugs and reporting them carefully. In many cases I got helpful response, sometimes the bug was acknowledged, and only once I was told to download a bug-fix for our Irix, for which we have the so-called premium-service (when you subscribe, you are told that you are will get all updates freely, but I was not expecting that I have to report the bug for it). The worst kind of answer you can get is "Yep, that's a known bug, but look, our development version 8.5 handles it nicely". My suggestion would be that there should be a public beta cycle for educational institutions so that Mathematica can be tested by people who really use the appraised mathematical features, with the offer of acceptable rebates for reported bugs. Well, this is probably too much to hope for. Matthias Weber