On Tuesday, April 12, 2016 at 2:50:01 PM UTC-4, Robert Dodier wrote: > > On 2016-04-09, Sergey V Kozlukov <ithesa...@gmail.com <javascript:>> > wrote: > > > (%i1) f(r,phi) := signum(r^2 - 4); > > 2 > > (%o1) f(r, phi) := signum(r - 4) > > (%i2) integrate(integrate(r*f(r,phi), r, 0, 3), phi, 0, 2*%pi); > > (%o2) - 9 %pi > > > > That's strange > > Yup. I've reported it to the Maxima bug tracker: > https://sourceforge.net/p/maxima/bugs/3123/ > Probably related: https://sourceforge.net/p/maxima/bugs/2242/ > > After some investigation, it appears there is a spurious pattern match > somewhere in the integrator -- a subroutine believes it sees an > expression it can handle, but it's mistaken. > > Note that fixing this bug will likely result in integrate returning a > noun expression. But that's OK for you guys, right? since then > abs_integrate will handle it. >
Oh dear. abs_integrate is something I now dread to think about; it is so very useful, and yet so very buggy with the Sage flags - see http://trac.sagemath.org/ticket/12731 :-( -- 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.
