Subject: integrate 'quotient by zero' error message
From: Stavros Macrakis
Date: Sun, 30 Oct 2011 18:39:08 -0400
On Sun, Oct 30, 2011 at 15:02, Edwin Woollett <woollett at charter.net> wrote:
> ...
> Evidently, all code writers like the phrase "quotient by zero" in an
> error message. Wouldn't "divide by zero" be more appropriate?
> Or even "Code fails to accomodate this case".
> And the message only seems appropriate as a debug message
> for code writers, not an informative message for the general user.
>
I don't know why there are quotation marks around 'quotient' and 'zero' --
I think that is new (and ugly).
The reason it is "quotient by zero" and not "divide by zero" is presumably
that a symbolic expression of the form EXPR/0 has been generated as an
intermediate result somewhere. That is a quotient whose denominator is
zero, a meaningless construction. Maxima is not actually trying to divide
a number by zero, but to handle a division-expression (a quotient) which is
malformed.
I agree that "quotient by zero" in itself is not a useful error message for
the end user. Maybe something like "Internal inconsistency detected,
calculation aborted: quotient by zero" would be better. Even better if
every instance of every error had a unique ID, so that when users report
errors, we can be sure we're seeing the same error they're seeing,
e.g. "Internal inconsistency detected, calculation aborted: quotient by
zero at PQ1234".
-s