Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1999
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1999

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

Search the Archive

Re: HELP: Plot[]ing composite functions

  • To: mathgroup at smc.vnet.net
  • Subject: [mg16007] Re: HELP: Plot[]ing composite functions
  • From: Paul Abbott <paul at physics.uwa.edu.au>
  • Date: Sat, 20 Feb 1999 02:52:01 -0500
  • Organization: University of Western Australia
  • References: <7ag4kt$b0q@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Alexander Sirotkin wrote:

> Simple question - after definition of a functions
> which looks like this "H[w] == Log[10, 1 + Exp[I2Pi w]]"
> I try to Plot[] it and get the "... not machine size real
> number at ..." error. 

Because you are trying to plot a complex-valued function.  Try

	H[w_] = Log[10, 1 + E^(I*2*Pi*w)]; 
	Plot[Abs[H[w]], {w, 0, 4}]; 

or, more efficiently,

	Plot[Evaluate[Abs[H[w]]], {w, 0, 4}]; 

Cheers,
	Paul

____________________________________________________________________ 
Paul Abbott                                   Phone: +61-8-9380-2734
Department of Physics                           Fax: +61-8-9380-1014
The University of Western Australia           
Nedlands WA  6907                     mailto:paul at physics.uwa.edu.au 
AUSTRALIA                        http://www.physics.uwa.edu.au/~paul

            God IS a weakly left-handed dice player
____________________________________________________________________


  • Prev by Date: Re: Fourier and FFT: Powers of 2 only?
  • Next by Date: Re: MyPrependTo
  • Previous by thread: RE: HELP: Plot[]ing composite functions
  • Next by thread: Generalized Cross Validation package?