[sage-devel] Re: Different results for numerical and symbolic integration

2022-10-24 Thread Pablo Vitoria
Thank you very much for the analysis. If I understand correctly, the bug is in this part of the integral: x*log(x)^4/(x^2 + 1) I will try to report the bug to maxima. But, as far I can see https://sourceforge.net/p/maxima/bugs/ is very quiet, with few answers to the reports. El lunes, 24 de o

[sage-devel] Re: Different results for numerical and symbolic integration

2022-10-24 Thread Frédéric Chapoton
where we can see that there is a factor 2 between the wrong symbolic value and the correct numeric value This should be filed as a bug in maxima. Le lundi 24 octobre 2022 à 21:24:30 UTC+2, Frédéric Chapoton a écrit : > and one more step : > > sage: integrate(x*log(x)^4/(x^2 + 1), x,0,1).n() > 1

[sage-devel] Re: Different results for numerical and symbolic integration

2022-10-24 Thread Frédéric Chapoton
and one more step : sage: integrate(x*log(x)^4/(x^2 + 1), x,0,1).n() 1.45817965567036 sage: (x*log(x)^4/(x^2 + 1)).nintegral(x,0,1) (0.7290898278351722, 2.48288156701193e-09, 357, 0) sage: integrate(-log(x)^4/(x^2 + 1), x,0,1).n() -23.9077878738501 sage: (-log(x)^4/(x^2 + 1)).nintegral(x,0,1) (-23

[sage-devel] Re: Different results for numerical and symbolic integration

2022-10-24 Thread Frédéric Chapoton
more study of the bug (coming from maxima) sage: C=x^2*(log(x))^4/((x+1)*(1+x^2)) sage: aa,bb=C.partial_fraction_decomposition() sage: integral(aa,x,0,1) -5/128*pi^5 + 45/64*zeta(5) sage: integral(bb,x,0,1) 45/4*zeta(5) sage: _+__ -5/128*pi^5 + 765/64*zeta(5) sage: _.n() 0.440633136273039 sage: aa

[sage-devel] Re: Invitation: Weekly 30-minute Sage developer calls on Jitsi

2022-10-24 Thread Matthias Koeppe
Another Sage developer call starting now. On Monday, October 17, 2022 at 11:21:01 AM UTC-7 Matthias Koeppe wrote: > Calls for Europe / Africa / Americas: > > Monday noon, 12:15pm San Francisco > Monday afternoon, 3:15pm New York > Monday evening, 21:15 Paris > https://meet.jit.si/VibrantTribesBea