MathGroup Archive 1997

[Date Index] [Thread Index] [Author Index]

Search the Archive

ParametricPlot Remark

  • To: mathgroup at smc.vnet.net
  • Subject: [mg7177] ParametricPlot Remark
  • From: Andrei Constantinescu <constant at athena.polytechnique.fr>
  • Date: Wed, 14 May 1997 01:11:12 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

 Hellow !

 ... so I just remarked a pretty unusual thing with ParametricPlot / 3D ,
 and theirs Automatic PlotPoints number !

 So lets resume: 

  ParametricPlot  - works fine giving nice smooth courbes ,

 wether

 ParametricPlot3D - samples largely giving a pretty zigzag form !

 SURE , I can be fitted by hand, ... and I did it ! But does someone 
 understand why this happens ?

 You have bellow a sample program of the Lorenz Equations in order to 
 test it !

  Have fun !

   a + andrei

 s = 10;
 b = 8/3;
 r = 167;

 tmax = 10;

 eq = { 
	x'[t] == s ( y[t] - x[t] ),
        y'[t] == r x[t] - y[t] - x[t] z[t],
	z'[t] == - b z[t] + x[t] y[t],
	x[0] == 0,
	y[0] == 1,
	z[0] == 0
 	}

 sol = NDSolve[ eq, {x,y,z} , {t, 0, tmax}, 
	MaxSteps -> 5000, StartingStepSize -> 0.001]

 ParametricPlot3D[ Evaluate[{x[t], y[t], z[t]} /. sol[[1]] ], {t,0,tmax}, 
	PlotRange -> All  ]
 ParametricPlot[ Evaluate[{z[t], x[t]} /. sol[[1]] ], {t,0,tmax} , 
	PlotRange -> All ]
 ParametricPlot[ Evaluate[{z[t], y[t]} /. sol[[1]] ], {t,0,tmax} , 
	PlotRange -> All ]
 ParametricPlot[ Evaluate[{x[t], y[t]} /. sol[[1]] ], {t,0,tmax} , 
	PlotRange -> All ]

______________________________________________________________________
  Andrei Constantinescu               constant at athena.polytechnique.fr   
                                                                       
  LMS Ecole Polytechnique                  tel:   (33)-1-69.33.33.30
  91128 PALAISEAU cedex - FRANCE           fax:   (33)-1-69.33.30.26    


  • Prev by Date: Re: Re: Font for Notebooks
  • Next by Date: Re: ordered pairs
  • Previous by thread: PlotLabel Printing Problems
  • Next by thread: Re: ParametricPlot Remark