Path: utzoo!utgpu!watserv1!watdragon!lion!ccplumb
From: ccplumb@lion.waterloo.edu (Colin Plumb)
Newsgroups: comp.sys.handhelds
Subject: Re: hp-48sx symbolic complex number bug
Message-ID: <21954@watdragon.waterloo.edu>
Date: 14 Mar 90 03:53:09 GMT
References: <1990Mar13.174255.2517@cec1.wustl.edu>
Sender: daemon@watdragon.waterloo.edu
Reply-To: ccplumb@lion.waterloo.edu (Colin Plumb)
Organization: U. of Waterloo, Ontario
Lines: 23

In article <1990Mar13.174255.2517@cec1.wustl.edu> ksr1492@cec1.wustl.edu (Kevin Scott Ruland) writes:
>   Someone posted hp's bug list earlier.  On it was a bug that incorrectly
>translates symbolic complex numbers in polar form to rectangular form.
>This bug was the only one present in the four current rom revisions.
>How does hp suggest "getting around" this bug? And, when do they expect
>to fix it?

The bug arises when entering a complex number in polar form, and
then only when you're using symbolic (lacking a value) variables.
Where you want r cis theta, it actually returns theta cis r.  The
solution is to transpose the arguments to the function.

I wouldn't call it a fatal bug.

>   This bug seems at least as serious as the 8x8 inversion bug and is
>preventing me from buying a 48sx today.

The 8x8 inversion bug isn't very serious, either... if you need to
invert larger matrices, divide by an identity matrix.  You might
lose a bit of accuracy, but you can define your own invert function
which calls INV on smaller matrices.
-- 
	-Colin