ContourPlot3D vs PlotQuadricSurface

*To*: mathgroup at yoda.physics.unc.edu*Subject*: ContourPlot3D vs PlotQuadricSurface*From*: SCHNEIDR at KNOX.BITNET*Date*: Thu, 8 Jul 1993 11:29 CST

Mark Pundurs from wri points out that ContourPlot3D will plot a quadric surface. This is correct and ContourPlot3D is a very nice command. However, it is slow and requires that the user knows the region on which to request the plot. To plot a quadratic, PlotQuadricSurface in KnoxPackages only requires that the user input the quadratic (assumed to be of the form q[x,y,z] = 0) and the variables. Timings on my Mac IIfx for the quadratic x^2 + y^2 + z^2 + x y + y z + z x = 1 are ContourPlot3D - 165 Seconds PlotQuadricSurface - 19 Seconds Moreover, PlotQuadricSurface also has options for drawing the axes and printing the simplified equation, the principal axes, and the type. KnoxPackages are available through MathSource (0204-512). Many new commands as well as revisions of existing commands are being completed this summer. The new packages will be available in August. Dennis M. Schneider Knox College Galesburg, IL 61401