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.

    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 didn't try to distinguish the different cases, but I've checked in a
change so that you now get:

(%i1) display2d:false;
Evaluation took 0.0000 seconds (0.0000 elapsed) using 32 bytes.
(%o1) false
(%i2) quad_qagi(exp(-(y-log(exp(y) + 1)/3)^2/2),y,minf,inf);

quad_qagi: Cannot numerically evaluate %e^-((y-log(%e^y+1)/3)^2/2) at 
         935.2606747597932
 -- an error. To debug this try: debugmode(true);

At least you can see what is causing the problem, instead of getting a
noun form for some unknown reason.

Ray