MathGroup Archive 2010

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

Search the Archive

Re: More /.{I->-1} craziness

  • To: mathgroup at
  • Subject: [mg106298] Re: More /.{I->-1} craziness
  • From: Vince Virgilio <blueschi at>
  • Date: Thu, 7 Jan 2010 02:34:10 -0500 (EST)
  • References: <> <hhhmn8$o9t$>

On Jan 6, 5:59 am, Richard Fateman <fate... at> wrote:


> What I would say is
> Because of the disparity in internal representations (see below) ,
> for replacements on parts of complex expressions, don't use /. ...  
> use  /. BetterRules[ ...]

This expects too much from ReplaceAll.

> or use transformation or selection programs such as Conjugate, Im, Re, .. .

Yes. Not unlike something Andrzej said elsewhere about
PolynomialReduce (others said similar as well).


Vince Virgilio

Incidentally, my FullForm of x+4*I differs from yours, if I read yours

In[1]:= x+4I//FullForm
Out[1]//FullForm= Plus[Complex[0,4],x]

  • Prev by Date: Integrate 'learns'?
  • Next by Date: Re: FullForm puzzle.
  • Previous by thread: Re: Re: More /.{I->-1} craziness
  • Next by thread: Re: More /.{I->-1} craziness