Additional control of the computation of orbits can be obtained with
the Orbits panel. With the mouse in the dstool command window and
using ,
select the Orbits... entry from the Panels
menu button. A new panel (figure
) will open.
The top two lines of the panel contain buttons Forwards, Backwards, Continue, and Clear All which correspond to the mouse actions within the view window already described.
Below these are several text fields which control essential
parameters. Edit the Plot: value to 100 and the Step Size:
to .001. Using ,
click on Forwards. 5000
points (the value in the Stop: field) will
still be computed but now at time intervals of .001 with only every
hundredth point plotted or stored in memory. You can monitor this by
watching the Final time entry in the Selected Point panel,
and noting the number of points in memory displayed to the right of
the Settings button in the main command window.
Now restore the Plot: field to 1 and the Step
Size: to .01. Clear the view window by clicking
Clear All inside the Orbits panel.
Open the abbreviated menu button to the right of
Stopping Condition. Replace the Fixed Steps entry currently
chosen by Event Stopping. Most of the text fields at the bottom
of the Orbits panel now darken indicating that their fields
are editable. Enter 0 in the lines to the right of
and
respectively.
Now click on the Forwards button once to make sure the direction is set, and then repeatedly Continue. Orbits will be computed until either x+y or x-y reaches 0 or 5000 points are computed. You'll be able to see the orbits wind around near the attractor, as you repeatedly continue them.
You can also select the Propagation... panel to control both the choice of integration algorithm and parameters for it.