MathGroup Archive 2004

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

Search the Archive

Re: Re: 3D plotting problem

  • To: mathgroup at smc.vnet.net
  • Subject: [mg51771] Re: [mg51743] Re: 3D plotting problem
  • From: Henning Heiberg-Andersen <Henning.Heiberg-Andersen at fi.uib.no>
  • Date: Mon, 1 Nov 2004 02:53:19 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

I am sorry that I was not clear enough about the nature of my problem, 
which I will try to illustrate by the following example:

If 'Cos' is replaced by 'Cosh' in the command

ContourPlot3D[Cos[Sqrt[x^2+y^2+z^2]],{x,-2,2},{y,0,2},{z,-2,2}]

an empty plot box appears.

It seems to me that it is problematic to make 3D contour plots
involving exponential functions, and I hope somebody can suggest
a remedy for this.

Best regards,
Henning Heiberg-Andersen

On Sun, 31 Oct 2004, Bill Rowe wrote:

> On 10/30/04 at 3:47 AM, Henning.Heiberg-Andersen at fi.uib.no (Henning
> Heiberg-Andersen) wrote:
> 
> >I find myself unable to make a 3D plot of the atomic 2p orbital
> 
> >f_z(2p,x,y,z;a)=z*Exp[-a*Sqrt[x^2+y^2+z^2]].
> 
> >As far as I can understand, 'ContourPlot3D' is the only option, but
> >it gives either an empty plot box or a flat sheet.
> 
> >Can anyone suggest a way out?
> 
> You did not make it clear exactly what you tried to plot. If it was the expression you posted, then try re-writting your function as
> 
> f[x_, y_, z_, a_] := z*Exp[-a*Sqrt[x^2 + y^2 + z^2]]
> 
> Here, I've eliminated the _z from the function name as Mathematica doesn't allow underscore characters in function names f_z is interpeted by Mathematica to be any expression with Head z given a name f, not what you want.
> 
> Changed the "(" to "[" to corespond to proper Mathematica syntax
> 
> dropped 2p from the arguements since it does not appear on the rhs
> 
> added a underscore to all of the other arguments. Using x_ is interpreted by Mathematica as being any valid expression and is given a local name of x
> 
> Replaced Set ("=") with DelayedSet (":=")
> --
> To reply via email subtract one hundred and four
> 
> 


  • Prev by Date: Re: MPS format, Linear Programming, and Optimization'MPSData
  • Next by Date: Re: newbie question on functions
  • Previous by thread: Re: 3D plotting problem
  • Next by thread: Re: Re: Re: 3D plotting problem