On 2/16/13 9:48 AM, Robert Dodier wrote:
> On 2013-02-16, Rupert Swarbrick <rswarbrick at gmail.com> wrote:
>
>> We could insert a call to REMOVE-DUPLICATES on the equation list before
>> deciding what to do, but I think this would be fooled by pretty
>> obviously identical equations (eg. x+y and y+x are different; x*(1+x)
>> and x+x^2 are different...). I'm not sure whether it makes much sense to
>> try and do anything cleverer - calling expand on the equations might be
>> a bit bonkers...
> Agreed on both points.
>
>> So, in my opinion, this isn't really a bug. The weird behaviour is that
>> SSOLVE returns a sort of partial result when it gets stuck and SOLVEX
>> returns an empty list. Weirdness like this is why I don't call solve()
>> in scripts and instead rely on eg. algsys() where at least I know what
>> I'll get if it fails.
> Hmm. I think SSOLVE should return an empty list if it can't find a
> solution.
I think we need to distinguish these cases:
1. Solve decides that there are no solutions.
2. Solve cannot find a solution.
I think these are currently distinguished in the case of the
single-equation solve
by returning, respectively, an empty list and an "unsolved" equation or
equations, i.e. not
of the form x= ... .
RJF
>
> best,
>
> Robert Dodier
>
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima