Re: Q: How to plot field lines?

*To*: mathgroup at smc.vnet.net*Subject*: [mg27323] Re: Q: How to plot field lines?*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 21 Feb 2001 03:16:52 -0500 (EST)*Organization*: Universitaet Leipzig*References*: <96irfd$dcr@smc.vnet.net> <HQIj6.5846$Rl5.43848@ralph.vnet.net> <96t9j6$ps1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, a) closed field lines are a bit difficult. b) have a look to the closed lines in : http://phong.informatik.uni-leipzig.de/~kuska/visualsupp/tornadof.wrl.gz http://phong.informatik.uni-leipzig.de/~kuska/visualsupp/cfloop3.wrl.gz http://phong.informatik.uni-leipzig.de/~kuska/visualsupp/benzene2.wrl.gz contact me personal if you need the details. The virtual reality pictures are a part of my scientific visulaisation lectures here. c) did you try the line integral convolution ? The code is at http://phong.informatik.uni-leipzig.de/~kuska/visualsupp/fastlic.tar.gz no field lines but very nice. Regards Jens Robert wrote: > > Jens-Peer Kuska wrote: > > > Hi, > > the extend graphics packages by Tom Wickham-Jones have > > 2d & 3d fieldlines > > > > http://www.mathsource.com/Content/Enhancements/Graphics/3D/0208-976 > > > > thanks, i know the package (i have got the book by the author, where the > package is described and also some examples are > given). > > the problem is that the package doesn't really do what i want: > > (1. there is an error in the package: the lines > > t2 = Part[ sol, 1, 0, 1, 2] ; > > must be changed to > > t2 = Part[ sol, 1, 0, 1, 1, 2] ;) > > 2. the package does quite ok if the field is rather simple and if there are no > closed field lines. > > but even with simple fields having closed lines, e.g. the magnetic field of a > single line current, the program has problems calculating > the field lines. > > 3. the programs doesn't really plot "field lines", but only gives a > quantitative picture of the field. in a "real" field line picture, you can > imply from the density of the field lines to the absolute value of the local > field vector. since with the package i have to choose the > distance from one line to another by myself, this calculation would have to be > done beforehand (therefore chosing the distance > according to a "constant flux" between two lines), which isn't simple in > general. of course, if i know the vector potential, the field > lines can easily be constructed via a 'contourplot', but i'd been interested > in a program which plots the lines directly from a given > vector field. > > i know that this problem isn't an easy task, but i hoped somehow somebody has > solved it before ... > > regards, robert