Re: Complex Variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg55422] Re: Complex Variables*From*: Peter Pein <petsie at arcor.de>*Date*: Wed, 23 Mar 2005 05:34:34 -0500 (EST)*References*: <d1on33$nbs$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

wwolfe18 at comcast.net wrote: > This has been annoying me for a while. > Is there a way to declare symbols to be real so that > Re[x + i y] gives x and Conjugate[x + i y] gives x - i y etc? > > Warren Wolfe > > > In[1]:= $Post = ComplexExpand[#1, TargetFunctions -> {Re, Im}] & ; In[2]:= Re[(x - I*y)^3] Out[2]= x^3 - 3*x*y^2 In[3]:= Re[x + I*y] Out[3]= x In[4]:= Conjugate[a - I*(x + I*y)] Out[4]= a + I*x + y If you're _really_ sure you want this expansion everytime you use Mathematica, you can put "$Post=... " into your init.m file (Mathematica book A.7.2 & A.8.2) -- Peter Pein Berlin