On Tuesday, April 15, 2014 9:58:51 PM UTC-7, jorges wrote: > > On Wednesday, 16 April 2014 01:24:25 UTC-3, John H Palmieri wrote: >> >> I'm guessing that the issue is that your integrand simplifies when q=1 -- >> at least one term becomes zero -- but you do the integral before doing this >> simplification. Maybe the symbolic integration is not valid when q=1. If >> you plug in the parameters before integrating, you get something very >> different from Sage. Adding these two lines >> >> qs=integral(((TVcoff(t))^2/moff).subs(**params),t, d*pi/omega, >> 2*pi/omega) # substitute before integrating >> Nqs = qs.subs(**params).n() >> >> gives me something close to Maple's answer: >> >> sage: Nps >> 1057.74513808638 + 3.42074504083530*I >> sage: Nqs >> 0.0164729319512844 + 5.58793544769287e-9*I >> >> Indeed, that looks good. I still don't understand what you mean by "the > symbolic integration is not valid when q=1". I would think substituting > before or after should not make a difference. >
It's possible, for example, that when doing the integration, it divides by q-1 to "simplify" some algebra. Maybe it does something else which turns out not to be valid when q=1. This is all just a guess, anyway. John Also, I remember that I attempted to simplify before integrating before, > mainly to speed up calculations, but had some bad experience with real > numbers and maxima. I can't recall the precise details right now, but after > that I "learned" to defer substitution to the very end. That is until now. > I love SAGE, but these things, i.e. having to know special cases and how to > handle them, make using it much more difficult, especially for a non-power > user as me. > Thanks for pointing out how to avoid this issue. > > Jorge > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
