I have run the code
var('x')
f1(x)=1/sqrt(x^3+2)
f2(x)=1/sqrt(x^4+2)
r1=RR(integrate(f1(x),(x,1,10^(10))))
r2=RR(integrate(f2(x),(x,1,10^(10))))
s1=RR(integrate(f1(x),(x,1,10^(11))))
s2=RR(integrate(f2(x),(x,1,10^(11))))
integrals_for_comparison=[[r1,r2],[s1,s2]]
integrals_for_comparison
on Sage Version 6.2, Release Date: 2014-05-06 on both a mac running OSX
10.9 and an old hp compaq running ubuntu 14.04, using
the notebook interface in both cases with Safari as the browser on the mac
and Firefox as the browser on the compaq.
In both cases, I obtained the result
[[1.82808026966879, 0.881569060342641], [1.82809394511342,
2.32149165988606e-7]].
The integrals to 10^(10) are being evaluated more or less correctly, as is
the integral of f1 to 10^(11), but the
integral of f2 to 10^(11) is wrong by about seven orders of magnitude.
Despite my question title, I do not actually know enough about how sage
handles this computation to know whether it is a
numerical integration bug or a bug in the numerical evaluation of elliptic
functions, but something is obviously wrong.
--
You received this message because you are subscribed to the Google Groups
"sage-support" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-support.
For more options, visit https://groups.google.com/d/optout.
