On 17 Sep., 22:45, Fredrik Johansson <[email protected]> wrote: > On Fri, Sep 17, 2010 at 12:48 AM, maldun <[email protected]> wrote: > > Do you see the problems?! These are caused by the high oscillation, > > but we get no warning. > > If you use scipy you would get the following: > > It is possible to get an error estimate back from mpmath, as follows: > > sage: mpmath.quad(lambda a: mpmath.exp(a)*mpmath.sin(1000*a), > [0,mpmath.pi], error=True) > (mpf('-0.71920642950258207'), mpf('1.0')) > sage: mpmath.quad(lambda a: mpmath.exp(a)*mpmath.sin(1000*a), > [0,mpmath.pi], maxdegree=15, error=True) > (mpf('-0.022140670492108779'), mpf('1.0e-37')) > > Currently it doesn't seem to work with mpmath.call (because > mpmath_to_sage doesn't know what to do with a tuple). > > The error estimates are also somewhat bogus (in both examples above -- > the first value has been capped to 1.0, if I remember correctly what > the code does, and the second is an extrapolate of the quadrature > error alone and clearly doesn't account for the arithmetic error). But > it should be sufficient to correctly detect a problem and signal a > warning in the Sage wrapper code in typical cases. > > I'm currently working on rewriting the integration code in mpmath to > handle error estimates more rigorously and flexibly. This will work > much better in a future version of mpmath. > > Fredrik
Thanks for your answer! That would be great if this would be fixed! Don't hesitate to ask me for help. I'm still a beginner, but can always help out with basic programming and testing! maldun -- To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
