DEplot3d_926w.mws
Mon Sep 26 14:16:10 MDT 2005

Reference Example 2.5.6 and also Example 3.3.1

This shows examples of

      time-state curve (??same as a world line??)

      orbit

      component curves

>

restart;

####################################################

>	with(plots, display):

>	with(DEtools, DEplot3d):

###############################################################

>	DE1 := D(x)(t) = 1 - y(t)^2;

>	DE2 := D(y)(t) = -x(t)^2;

>	SYS := {DE1, DE2}:  VARS := {x(t), y(t)}:

>	IC := [[ x(0) = -1, y(0)= 1/2]]:

>	TRG := -5..5:  XRG := -2..2:  YRG := TRG:

>	OPT := scene=[t, x(t), y(t)]:

>	Nerk := DEplot3d(SYS, VARS, t=TRG, IC, x=XRG,  y=YRG, OPT):

The following plot, named Nerk, gives the "time-state curve" in xyt-space:

>	display(Nerk);

>	display(Nerk, orientation=[0,90]);   The "orbit" in xy-space

>	display(Nerk, orientation=[90,90]);   The ty-space "component curve"

>	display(Nerk, orientation=[-90,0]);   The tx-space "component curve"