a needs to be positive for polar_lift to reduce. The result is correct, but it doesn't reduce to 1 unless a is positive.
I'm not sure what the abs(periodic_argument(1/polar_lift(a), oo)) <= pi/2 reduces to. Aaron Meurer On Fri, Jul 11, 2014 at 12:23 PM, Ondřej Čertík <[email protected]> wrote: > Hi ab0c1d0ef, > > On Fri, Jul 11, 2014 at 11:02 AM, <[email protected]> wrote: >> Dear user and developers, >> >> I'm new to sympy and tried a few things out, of course I stumbled across >> smth I coudln't understand. >> So here is my question: >> >> If I define an expression like >> g=sqrt(a/pi)*exp(-a*x**2) >> and integrate it like >> integrate(g,(x,-oo,oo)) >> I get the expected result (1). >> >> But if I integrate an expression like >> g=sqrt(1/a/pi)*exp(-x**2/a) >> and integrate it the same way I get >> ( a * sqrt(1/a) ) / sqrt(polar_lift(a)) >> >> I must admit I'm a little bit frightened by the polar_lift function because >> I've never heard of it, but it seems to give the argument of a complex >> number. Is this correct? >> But then I don't understand why for >> a=Symbol('a',real=True) >> g=sqrt(1/a/pi)*exp(-x**2/a) >> simplify(integrate(g,(x,-oo,oo))) >> I still don't get 1 as a result. > > Thanks for reporting this, I think you might have discovered a bug. > Btw, this is what I get with the latest master: > > https://gist.github.com/certik/cd8cd4c0a7f0ba04c719 > > But it still shows the behavior you described. > > Ondrej > >> >> Would be nice to know. >> Thanks in advance. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sympy. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/b8b2b9f1-596c-416d-a0e9-bb3d17bb6b15%40googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/CADDwiVB580qeT9gmHFGM_ugDssxiWY4cRP9KJVwTV44ppwVaag%40mail.gmail.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6%2BT1kbO98V%3D1XSv7CjKCNFePDgK0Ri7dNkB%2BSe-K_8VmQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
