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