MathGroup Archive 1997

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

Search the Archive

RE: Beginner's Question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg9876] RE: [mg9869] Beginner's Question
  • From: Jean-Marie THOMAS <jmthomas at cybercable.tm.fr>
  • Date: Sun, 30 Nov 1997 00:39:27 -0500
  • Sender: owner-wri-mathgroup at wolfram.com

The function Chop can help you:

m=Table[Random[Complex],{5},{5}]
im=Inverse at m

This should evaluate to a Identity Matrix, but numerical computation
leaves very small numbers: im.m

Using Chop removes these small numbers: Chop[%]

-----Message d'origine-----
De:	Henri Kowalczyk [SMTP:hkowalc at eng.clemson.edu] Date:	samedi 29
novembre 1997 06:11
A:	mathgroup at smc.vnet.net
Objet:	[mg9869] Beginner's Question

I'm using mathematica to do some matrix manipulation of matrices with
symbolic elements. I end up with elements having elements that evaluate
to zero, but instead of zero I get something like 

0.X+0.Y

so my matrices become large with uneeded elements... is there a setting
I can change so it will automatically evaluate these to zero?



  • Prev by Date: Re: outputting lists to a file
  • Next by Date: 3D Arrows
  • Previous by thread: Re: Beginner's Question
  • Next by thread: EulerPhi[1]