RE: problems with ContourPlot
- To: mathgroup at smc.vnet.net
- Subject: [mg33633] RE: [mg33616] problems with ContourPlot
- From: "David Park" <djmp at earthlink.net>
- Date: Thu, 4 Apr 2002 19:39:50 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Harald, Where Fortran has ** for power, Mathematica uses ^. Just make the change and it will work. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ > From: Harald von der Osten-Woldenburg [mailto:hvdosten at lb.netic.de] To: mathgroup at smc.vnet.net > > > Hi out there, > > > if I try this: > > > a := 0.5; b := 0.5; c := 0.5; y := 0.0; > > ContourPlot[(x*(x - a) + y*y + z*z)/ (Sqrt[(x*x + y*y + z*z) ** 3]* > Sqrt[((x - a) ** 2 + y*y + z*z) ** 3]) - ((x - a)*(x - a - b > -c) + > y*y + z*z)/ (Sqrt[((x - a) ** 2 + y*y + z*z) ** 3]* > Sqrt[((x - a - b - c) ** 2 + y*y + z*z) ** 3]) - (x*(x - a -b) > + > y*y + z*z)/ (Sqrt[(x*x + y*y + z*z) ** 3]* > Sqrt[((x - a - b) ** 2 + y*y + z*z) ** > 3]) + ((x - a - b)*(x - a - b - c) + y*y + > z*z)/(Sqrt[((x - a - b) ** 2 + y*y + z*z) ** 3]* > Sqrt[((x - a - b - c) ** 2 + y*y + z*z) ** 3]), {x, -1, 1}, > {z, 0, 1}, Contours -> {0, 1, 5, 10, 50, 100}, ContourShading -> False] > > > > > I receive the error-messages: > > > > [ ...Expression... ] is not a machine-size real number at {x, z} = > {-1.,0.} > > > ContourGraphics::"ctpnt": "The contour is attempting to traverse a cell > in which some of the points have not evaluated to numbers, and it will > be dropped." > > > General::"stop": "Further output of (ContourGraphics :: "ctpnt") will be > suppressed during this calculation." > > > > > > Because I compiled this also with Fortran I know that there are also > results in the range up to 10^6. Is this too much for ContourPlot? Or > did I some crazy things.... ?? At (-1,0.) I cannot find any > singularity... > > > > Thank you very much for any small hint. > > Harry > > > > > > > > -- > Harald von der Osten-Woldenburg > Geophysical Prospection of Archaeological Sites > National Heritage Department of Baden-Wuerttemberg > Silberburgstrasse 193, D-70178 Stuttgart > Fax Office: +49-(0)711-1694-707 > http://www.lb.netic.de/hvdosten : Geomagnetics, Geoelectrics, Radar, EMI > > > > >