Re: Q: How to plot field lines?

*To*: mathgroup at smc.vnet.net*Subject*: [mg27318] Re: Q: How to plot field lines?*From*: Robert <robert.schuerhuber at gmx.at>*Date*: Tue, 20 Feb 2001 03:05:28 -0500 (EST)*Organization*: Vienna University of Technology*References*: <96irfd$dcr@smc.vnet.net> <HQIj6.5846$Rl5.43848@ralph.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

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