On 2016-04-09, Sergey V Kozlukov <ithesabot...@gmail.com> 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. best Robert Dodier PS. By the way, I'm temporarily at liberty, as unemployed actors like to say; if you or someone you know needs someone who can do interesting things with math, statistics, computer programming, etc., feel free to drop me a line (robert.dod...@gmail.com). -- 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.
