When Does quad_qagi Evalute?



>>>>> "Robert" == Robert Dodier <robert.dodier at gmail.com> writes:

    Robert> On 2013-08-28, Raymond Toy <toy.raymond at gmail.com> wrote:
    >> I think it would be nice if maxima indicated that somehow instead of
    >> just returning a noun form.  Users should have to trace internal
    >> functions to figure that out.

I meant "shouldn't have to", of course.

    Robert> Agreed. I wonder if Maxima can distinguish integrands which don't
    Robert> evaluate to a number but which might (e.g. unbound variable), from
    Robert> those which can't (e.g. floating point error), and print different
    Robert> messages for those.

I think this is all buried in coerce-float-fun.  For gcl, any errors
cause the function to return T.  For other lisps, we do distinguish
between an arithmetic-error and a maxia-$error, but return T in both
cases anyway.

I'm not sure what the best way for coerce-float-fun to distinguish
between the two cases.  And in any case, gcl can't so that seems not
an option.

For the quad routines, I think the best we can do now would be to
detect a non-numerical result and signal a maxima error.

Ray