On Wed, Jun 3, 2015 at 9:40 AM, kcrisman <kcris...@gmail.com> wrote: >> >> Something is happening in the interface, yes, but >> > > Apparently sympy can't do it either (?). Here is my experiment. >
Sorry, I don't see how your code below is testing Sympy. I got a wrong answer (namely, -sqrt(2), when I think a correct answer is 2-sqrt(2)) for >>> integrate(sqrt(cos(x)**2),(x,pi/4,3*pi/4)) It would not evaluate >>> integrate(sqrt(cot(x)**2),(x,pi/4,3*pi/4)) > sage: from sage.symbolic.integration.external import maxima_integrator > sage: maxima_integrator(sqrt(cot(x)^2),x) > -1/2*log(tan(x)^2 + 1) + log(tan(x)) > sage: maxima_integrator(cot(x),x) > log(sin(x)) > sage: maxima_integrator(sqrt(cot(x)^2),x,pi/4,3*pi/4) > 0 > sage: maxima_integrator(cot(x),x, pi/4,3*pi/4) > 0 > sage: f(x) = maxima_integrator(sqrt(cot(x)^2),x) > sage: f(pi/4) > -1/2*log(2) > sage: f(3*pi/4) > I*pi - 1/2*log(2) > > so I see already a problem there, though not the same problem exactly. Note > that > > (%i6) sqrt(cot(x)^2); > (%o6) abs(cot(x)) > > which is a good sign, but in a fresh start > > (%i1) domain:complex; > (%o1) complex > (%i2) sqrt(cot(x)^2); > 2 > (%o2) sqrt(cot (x)) > (%i3) integrate(sqrt(cot(x)^2),x,%pi/4,%pi/4*3); > (%o3) 0 > > So this is indeed a Maxima bug, I guess. > http://trac.sagemath.org/ticket/18599 > > Greg, always good to hear from you! Such doctests could be useful, but (as > you know) the difference between ones that are possible to integrate > symbolically and those which aren't is pretty tricky to navigate, so I don't > know how to generate them randomly. If you have some specific integrals to > propose, of course, please open a ticket (I think you have a Trac account?) > and we can definitely include more in our tests. > > - kcrisman > > -- > 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 http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
