
R: complex conjugation by star
Posted:
Apr 20, 2014 4:46 AM


Dear Dave, many thanks again. Now I have the problem to tell Mathematica that same variables are reals and have not to be 'starred' so that (x+Iy+z)* is not x*+Iy*+z* but xIy+z* (if x and y are reals and z unknown. Command like Element[x, Reals] does not work. Sincerely yours Roberto
Messaggio originale Da: Dave Snead [mailto:dsnead6@charter.net] Inviato: venerd=EC 18 aprile 2014 09:30 A: Brambilla Roberto Luigi (RSE); mathgroup@smc.vnet.net Oggetto: Re: complex conjugation by star
Rob 
This will give you what you want:
SuperStar[f_?NumberQ]:=Conjugate[f] SuperStar[f:_[___]]:=SuperStar/@f
Cheers, Dave Snead
Original Message From: Brambilla Roberto Luigi (RSE) Sent: Thursday, April 17, 2014 10:46 PM Subject: complex conjugation by star
I have defined the following useful star complexconjugation (common star exponent notation)
f_*:=f/.Complex[u_,v_]>Complex[u,v]
and it works fine. For example BesselJ[2,x+I y]* gives BesselJ[2,xI y] etc. ..(x,y defined/undefined). Also it is listable on number lists
{1+i2, 5+i6}* gives {1i2, 5i6} .
Unfortunately it does not work on symbols, i.e. A* gives A even if I have defined A as a complex number by means of Element[A, Complexes]. Similarly if I define Element[{A,B,G}, Complexes]
{A,B,G}* gives {A,B,G} and (A+B+G)* gives A+B+G.
I'd like to obtain {A*,B*,G*} and A*+B*+G* ( ! )
Is it possible to fix this deficiency, unpleasant in manipulating general expressions where is not known if symbols represent real or complex variables?
Many thanks! Rob

