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
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