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From: edp@jareth.enet.dec.com (Eric Postpischil (Always mount a scratch monkey.))
Newsgroups: comp.sys.handhelds
Subject: Re: Possible bug with ISOL and SOLVE
Message-ID: <15990@shlump.nac.dec.com>
Date: 12 Oct 90 12:49:40 GMT
References: <4155@tellab5.tellabs.com>
Sender: newsdaemon@shlump.nac.dec.com
Reply-To: edp@jareth.enet.dec.com (Eric Postpischil (Always mount a scratch monkey.))
Organization: Digital Equipment Corporation
Lines: 19

In article <4155@tellab5.tellabs.com>, ram@tellabs.com (Bob Martin) writes:

>When I solve for NUMP (having supplied sane values for PV, INTPP, and PMT),
>I get an error - "Bad guess(es)".  ????  What's going on?  So I edit the
>equation to remove the "+2*pi*i*n1" term, go back into SOLVR and recalculate,
>and everything works fine. 

When the solver evaluates your expression, it temporarily forces
numerical-evaluation mode.  In evaluating the expression '2*pi*i*n1', the
complex number (0,1) is used for 'i'.  Even though n1 is 0, the result returned
is the complex number (0,0) rather than the real number 0.  As a result, the
solver gets back a complex number for the whole expression.  It doesn't like
that.

I tested this conjecture by changing 'i' to 'I' and setting it to 1; the solver
was happy.


				-- edp