On 10/5/11 4:17 PM, Edwin Woollett wrote:
> Using my prev. message code for nint, which will
> call quad_qags for this example, I get results which
> agree with Mma's pdf tutorial on advanced numerical
> integration
> (http://www.wolfram.com/learningcenter/tutorialcollection/AdvancedNumericalIntegrationInMathematica/)
>
>
> for the integrand (p. 2, pdf 5)
>
> (x-2)^2 * sin (4000*x),
> over the interval (x,2,3) by using the default epsabs=0.0,
> epsrel = 1.0e-8, so only epsrel plays a role, but I get
I don't think that's true. If you set epsabs to 0, then you are telling
quadpack that you want to get an absolute error of 0. I don't recall
how epsabs and epsrel interact, though.
> ------------------------------------------------
>
> So, I am wondering if there is some global parameter
> which will allow me to turn off the automatic
> messages from slatec??
No, I don't think there is currently a way to do that, but from looking
at the code it shouldn't be hard.
>
> For this type of integral, the epsrel control parameter is
> a better choice, but leads to unwanted error messages.
For the standard quadpack interface, I can see where it might be useful
to turn off the messages because the return code is part of the answer
so you can tell if the integration was apparently ok or not. But with
your nint (which reminds of Fortran nint/aint, not numerical
integration), there's no indication that anything went wrong, except if
quadpack prints out the error message.
I would not be happy to use such an interface.
Ray