Re: ParametricPlot Question

*To*: mathgroup at smc.vnet.net*Subject*: [mg37149] Re: [mg37135] ParametricPlot Question*From*: Bill Rowe <listuser at earthlink.net>*Date*: Sun, 13 Oct 2002 05:56:36 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

On 10/12/02 at 5:05 AM, charlesmorgan at attbi.com (Charles Morgan) wrote: >I would like to mark representative samples of t on a parametric plot, >where t is the third parameter. For example, how could I mark the 8 >values t=0, t=Pi/4, ..., t=7Pi/4 on the plot generated by: >ParametricPlot[{Sin[t], Cos[t]}, {t, 0, 2Pi}] There are a number of possibilities depending on exactly how you want things to appear You could use the GridLines option to construct a grid with intersections at the desired points, i.e., GridLines->{Cos[# Pi/4]&/@Range[0,7],Sin[# Pi/4]&/@Range[0,7]} You could use Ticks->{Cos[# Pi/4]&/@Range[0,7],Sin[# Pi/4]&/@Range[0,7]} combined with Axes->True and seting AxesOrigin to an appropriate location Another option would be using Epilog->MapThread[Point[{#1,#2}]&,Cos[# Pi/4]&/@Range[0,7],Sin[# Pi/4]&/@Range[0,7]}] to plot points at the key locations. In order to get a satisfactory display you may also need to adjust either PointSize or PlotStyle. Other options include making plots of the marks and the parametric plot as separate graphics then combining them with the Show command