On Wednesday, January 4, 2017 at 8:24:22 PM UTC, Eric Gourgoulhon wrote: > > Hi Samuel, > > Le mercredi 4 janvier 2017 20:49:54 UTC+1, Samuel Lelievre a écrit : >> >> >> >> It's of course a good thing to track the issue, but on the other side, >> why work in the Symbolic Ring? >> >> > It's because I need to consider sqrt(-z), so that I cannot stay with > rational functions. >
I woud have picked one more variable, w, and set w^2=-z. Now everything is polynomial again... > Actually sqrt(-z) is the volume element of the Tomimatsu-Sato 3-metric: > > http://nbviewer.jupyter.org/github/sagemanifolds/SageManifolds/blob/master/Worksheets/v1.0/SM_Tomimatsu-Sato_3p1.ipynb > Note that, despite this issue with the volume element, Sage is doing > pretty well with this complicated metric (see e.g. the huge expression of > the Ricci scalar in Out[24]): all Einstein equations are passed. > > Best regards, > > Eric. > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
