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Re: Integrate without Simplify

  • To: mathgroup at
  • Subject: [mg43949] Re: Integrate without Simplify
  • From: Paul Abbott <paul at>
  • Date: Wed, 15 Oct 2003 04:59:25 -0400 (EDT)
  • Organization: The University of Western Australia
  • References: <bl0urk$405$>
  • Sender: owner-wri-mathgroup at

In article <bl0urk$405$1 at>, k.junk at (Kevin VW) 

> I have about 10000 term in a list that I want to integrate. 

Let me guess -- each term is of certain form? And can this particular 
form be integrated in a generic fashion? If so, then you can, and 
should, use pattern-matching to perform the integral. For example, if 
you have 10000 terms of the form

   x^n Exp[-a x]

with different n and a, and you need to compute the integral with 
respect to x over [0,Infinity). The generic integral is then

  n! / a^(n+1)

and the 10000 term list can be integrated by pattern-matching

  longlist /. x^(n_) Exp[a_ x] :> n! / (-a)^(n+1)


Paul Abbott                                   Phone: +61 8 9380 2734
School of Physics, M013                         Fax: +61 8 9380 1014
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