Re: Re: Re: 3D plotting problem
- To: mathgroup at smc.vnet.net
- Subject: [mg51784] Re: [mg51771] Re: [mg51743] Re: 3D plotting problem
- From: DrBob <drbob at bigfoot.com>
- Date: Tue, 2 Nov 2004 02:05:04 -0500 (EST)
- References: <200411010753.CAA06509@smc.vnet.net>
- Reply-to: drbob at bigfoot.com
- Sender: owner-wri-mathgroup at wolfram.com
Documentation is unclear on what ContourPlot3D actually does--until you get to the example. You also get an empty box if you replace Cos[...] with 1-Cos[...], simply because 1-Cos[...] is never zero in the range. But this gives a surface: ContourPlot3D[3 - Cosh[Sqrt[ x^2 + y^2 + z^2]], {x, -2, 2}, {y, 0, 2}, {z, -2, 2}] and so does this: ContourPlot3D[1.01 - Cosh[Sqrt[x^2 + y^2 + z^2]], {x, -2, 2}, {y, 0, 2}, {z, -2, 2}] That's a weird one. Bobby On Mon, 1 Nov 2004 02:53:19 -0500 (EST), Henning Heiberg-Andersen <Henning.Heiberg-Andersen at fi.uib.no> wrote: > > > > 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 >> >> > > > > -- DrBob at bigfoot.com www.eclecticdreams.net
- References:
- Re: Re: 3D plotting problem
- From: Henning Heiberg-Andersen <Henning.Heiberg-Andersen@fi.uib.no>
- Re: Re: 3D plotting problem