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

Re: Replace certain variable

• To: mathgroup at smc.vnet.net
• Subject: [mg74843] Re: Replace certain variable
• From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
• Date: Sat, 7 Apr 2007 04:08:53 -0400 (EDT)
• Organization: The Open University, Milton Keynes, UK
• References: <ev51a7$a63$1@smc.vnet.net>

KFUPM 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.
[snip]

A transformation rule appears to be well suited for such a task. For 
instance,

F[w]*Exp[I*w*t] + G[w]*Exp[w*omega^2] + 2*H[w]*Exp[I*w*t] /. 
Exp[(p___)*w*(q___)] -> Exp[p*(x + s*a)*q]

E^(I*t*(a*s + x))*F[w] + E^(omega^2*(a*s + x))*G[w] + 2*E^(I*t*(a*s + 
x))*H[w]

HTH,
Jean-Marc