Re: PlotPoints in plot

*To*: mathgroup at smc.vnet.net*Subject*: [mg48549] Re: PlotPoints in plot*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Sat, 5 Jun 2004 07:18:50 -0400 (EDT)*Organization*: The University of Western Australia*References*: <c9pe8k$psr$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <c9pe8k$psr$1 at smc.vnet.net>, mathma18 at hotmail.com ("G.L.Narasimham") wrote: > For the plot command Plot[Sqrt[1-x^2],{x,-1,1},PlotPoints->3] > I expected to see a triangle joining 3 points on a circle, but a > continuous line ( default PlotPoints->20? )appears. However, > ParametricPlot3D[{Cos[t],Sin[t],0},{t,0,Pi},PlotPoints->3,ViewPoint->{0,0,5}] > gives a triangle. How to get a polygon of straight sides in the > unparametered Plot? I am struggling to understand _why_ you would want to do this? Anyway, I don't think that it is possible to do this using Plot _directly_ because of restrictions on PlotPoints (and PlotDivision). The closest I can get is to use the PlotDivision option: Plot[Sqrt[1 - x^2], {x, -1, 1}, PlotPoints -> 3, PlotDivision -> 1] However, this is not quite what you want. Alternatively, int = Interpolation[Table[{x, Sqrt[1 - x^2]}, {x, -1, 1}], InterpolationOrder -> 1] Plot[int[x], {x, -1, 1}]; Cheers, Paul -- Paul Abbott Phone: +61 8 9380 2734 School of Physics, M013 Fax: +61 8 9380 1014 The University of Western Australia (CRICOS Provider No 00126G) 35 Stirling Highway Crawley WA 6009 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul