Services & ResourcesWolfram ForumsMathGroup Archive

[Date Index] [Thread Index] [Author Index]

Re: Complex conjugate differentiation

• To: mathgroup at smc.vnet.net
• Subject: [mg107185] Re: [mg107163] Complex conjugate differentiation
• From: Daniel Lichtblau <danl at wolfram.com>
• Date: Fri, 5 Feb 2010 03:20:42 -0500 (EST)
• References: <201002041128.GAA29970@smc.vnet.net>

Paperorbifold wrote:
> In[1]:=D[z z*, z*]
> Out[1]=z
> where z*=Conjugate[z], while
> In[2]:=D[z z*, z]
> Out[2]=Conjugate[z] + z Conjugate'[z]
> My question is: which is the best way to get as output
> Out[2]=Conjugate[z]?
> Should I properly define StarProduct or is there another even
> straightforward solution?
> Thanks a lot.

Not sure if this is optimal, but I'd recommend using a different 
variable to denote Conjugate[z] (your z*), then substituting for it 
afterward.

Example:

In[10]:= D[z*w, z] /. w -> Conjugate[z]
D[z*w, w] /. w -> Conjugate[z]

Out[10]= Conjugate[z]

Out[11]= z

There might be alternatives using Symbolize from the Notations` package.

Daniel Lichtblau
Wolfram Research

• References:
  • Complex conjugate differentiation
    • From: Paperorbifold <kgodelNOSPAM@liberoNOSPAM.it>