MathGroup Archive 2011

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

Search the Archive

Re: Approximation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg116479] Re: Approximation
  • From: Alexei Boulbitch <alexei.boulbitch at iee.lu>
  • Date: Wed, 16 Feb 2011 06:44:41 -0500 (EST)

The operators Series[]//Normal will do the job for you. For example:

expr = 1/Sqrt[R^2 + G^2];
Simplify[Series[expr, {R, 0, 2}], Assumptions ->  G>  0]
Simplify[Series[expr, {R, 0, 2}] // Normal, Assumptions ->  G>  0]

SeriesData[R, 0, {G^(-1), 0, Rational[-1, 2] G^(-3)}, 0, 3, 1]

1/G - R^2/(2 G^3)

Have fun. Alexei


Is there a way to tell Mathematica to simplify and approximate an
expression assuming things such as "R is a lot smaller than G"/ R<<G ?
If not so, how would you approach the problem?

Thanks

-- 
Alexei Boulbitch, Dr. habil.
Senior Scientist
Material Development

IEE S.A.
ZAE Weiergewan
11, rue Edmond Reuter
L-5326 CONTERN
Luxembourg

Tel: +352 2454 2566
Fax: +352 2454 3566
Mobile: +49 (0) 151 52 40 66 44

e-mail: alexei.boulbitch at iee.lu

www.iee.lu

--

This e-mail may contain trade secrets or privileged, undisclosed or
otherwise confidential information. If you are not the intended
recipient and have received this e-mail in error, you are hereby
notified that any review, copying or distribution of it is strictly
prohibited. Please inform us immediately and destroy the original
transmittal from your system. Thank you for your co-operation.



  • Prev by Date: Re: Replace elements in a matrix
  • Next by Date: Re: How to do quickest
  • Previous by thread: Re: Approximation
  • Next by thread: Re: Approximation