Re: Drawing multiple curves with ParametricPlot3D
- To: mathgroup@smc.vnet.net
- Subject: [mg10587] Re: [mg10539] Drawing multiple curves with ParametricPlot3D
- From: jpk@max.mpae.gwdg.de
- Date: Mon, 26 Jan 1998 04:42:21 -0500
Hi Volker,
> For plotting several objects together, the documentation says:
>
> ParametricPlot3D[{{fx,fy,fz},{gx,gy,gz},...},...]
>
> but
>
> ParametricPlot3D[
> {Evaluate[{r1x[t],r1y[t],r1z[t]}/.%],
> Evaluate[{r2x[t],r2y[t],r2z[t]}/.%],{t,0,dt}},{t,0,dt}]
>
> doesn't work at all.
No surprise, suppose You had dsol=NDSolve[some equations ...]
the command
ParametricPlot3D[
Evaluate[{{r1x[t],r1y[t],r1z[t]},
{r2x[t],r2y[t],r2z[t]}}/.Flatten[dsol]],{t,0,dt}]
works.
NDSolve ives You a List[] of solutions so that in the case of more than
one solution x /. {{x->xs1},{x->xs2}} gives You a list of {xs1,xs2}. So
You must flatten out the output of NDSolve. Second Evaluate[] is needed
for the whole first argument -- so that the pattern matching for
ParametricPlot3D[] can go to the case for more than one curve.
Hope that helps.
Jens