Re: Symbolic complex conjugation?
- To: mathgroup at smc.vnet.net
- Subject: [mg89967] Re: Symbolic complex conjugation?
- From: dh <dh at metrohm.ch>
- Date: Wed, 25 Jun 2008 06:28:41 -0400 (EDT)
- References: <g3q7vb$aus$1@smc.vnet.net>
Hi,
pattern matching can sometimes be a bit tricky. But it jusually helps to
look at the expression using FullForm. You will see that in the first
expression we have Complex[0,1] what is eqaul to I, but in the second
expression we have Complex[0,-1] what equals -I. Therefore, you should
replace -I->I.
hope this helps, Daniel
AES wrote:
> I'm sorry, but I just don't understand why the following test case works
> just fine:
>
> [In copying it, I've substituted "Isymbol" for the \[ImaginaryI] that
> actually appears in the Out[] cells.]
>
> In[202]:= eqna={a+I b==0};
> solna=Solve[eqna,b];
> b=b/.solna[[1]];
> bStar=b/.{I->-I};
> {b, Star}
>
> Out[205]={ -Isymbol a, Isymbol a }
>
> but the actual calculation that prompted the test case doesn't:
>
> In[206]:= eqnp={((dwa/2)+I(w-wa))p-I (kappa/(2 w))dN e==0};
> solnp=Solve[eqnp,p];
> p=p/.solnp[[1]];
> pStar=p/.{I->-I}
>
> Out[208]= { (dN e kappa)/(w (-Isymbol dwa+2 w-2 wa)),
> (dN e kappa)/(w (-Isymbol dwa+2 w-2 wa)) }
>
> And actually, I guess my real concern is not understanding "how it
> happens" -- but more "how it can happen" that Mathematica can do
> something this potentially damaging to some innocent user.
>
--
Daniel Huber
Metrohm Ltd.
Oberdorfstr. 68
CH-9100 Herisau
Tel. +41 71 353 8585, Fax +41 71 353 8907
E-Mail:<mailto:dh at metrohm.com>
Internet:<http://www.metrohm.com>