On Nov 29, 3:36 pm, Burcin Erocal <[email protected]> wrote: > On Tue, 29 Nov 2011 13:14:36 -0700 > > > > > > > > > > [email protected] wrote: > > Hi! I'm working with an expression involving imaginary exponentials > > and their conjugates: > > > exp(i•k•x) > > > exp(i•k•x)*=exp(-i•k•x) > > > However, when multiplying them together, I do not get the arguments > > to evaluate to zero. My variables x and k are real, and I've told > > sage to assume that they are real. But it will not evaluate: > > > exp(i•k•x)•(exp(i•k•x))* > > > as: > > > exp(i•k•x+(i•k•x)*)=exp(i•k•x+(i*•k*•x*))=exp(i•k•x+(-i•k•x))=exp(i•k•x-i•k > > •x)=exp(0)=1. > > > Any ideas? > > Try this: > > sage: var('x',domain=RR) > x > sage: var('k',domain=RR) > k > sage: exp(i*x*k) > e^(I*k*x) > sage: exp(i*x*k)*exp(-i*x*k) > 1 > > The assume() system is from maxima. Unfortunately, basic arithmetic with > symbolic expressions doesn't know about these. It uses a different > system as you can see. > > There must be a ticket to make these two assumption systems play nice, > but I can't find it ATM.
I'm not sure about this. I'm not even sure how compatible they would be ... -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
