MathGroup Archive 2007

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

Search the Archive

Re: Replace certain variable

  • To: mathgroup at smc.vnet.net
  • Subject: [mg74833] Re: Replace certain variable
  • From: jesse.woodroffe at gmail.com
  • Date: Sat, 7 Apr 2007 04:03:45 -0400 (EDT)
  • References: <ev51a7$a63$1@smc.vnet.net>

Although I suspect there may be even cleaner ways to do it, you could
use a replacement rule such as

F[w]*Exp[I*w*t]/.{Exp[g:(restOfExponent__*w)]->Exp[restOfExponent*(x
+s*a)]}

This rule works for any sequence of multiplications in the exponent,
so long as w is somewhere and there actually IS a multiplication, i.e.
it doesn't work for w alone. To remedy that situtation, you could also
include a specific replacement for Exp[w],

Exp[w]->Exp[x*s+a]

This being said, I'd guess that there's a way that would get both
cases at once.


Jesse Woodroffe

On Apr 6, 3:44 am, "KFUPM" <hussain.alqaht... at gmail.com> wrote:
> Dear Group
>
> If i have a term like : F[w]*Exp[I*w*t] where F[w] is an arbitrary
> function, and i want to replace w by x+ s*a only in the exponent not
> in F[w], i wonder what is the quickest and easiest way to do it
> provided that i have so many similar terms.
>
> Your help and prompt reply is highly appreciated.
>
> HMQ




  • Prev by Date: Re: Optimal variable selection in multiple linear regression ?
  • Next by Date: Re: Replace certain variable
  • Previous by thread: Re: Replace certain variable
  • Next by thread: Multivariate polynomial elimination question