Move your mouse into the view window and click .
Dstool will remember this selected point until you explicitly
choose another. Now click
in the view window.
Figure
shows a typical result. By default,
dstool will compute 5000 points forward along the trajectory starting at the
previously selected point. The points will be equally spaced at time
intervals of .01. We'll see shortly how to change these parameters. To
the right of the Settings button on the command window,
you'll see the number of points currently stored by dstool. Each time
you click
another 5000 points are computed and displayed.
If you're using a color monitor, all points of this orbit will
be drawn in the first color of dstool's palette. Now click
at another location in the canvas of the view window.
Clicking
will plot 5000 points on the orbit from the newly
selected point. On a color monitor, this orbit will automatically be
displayed in the next color of dstool's palette.
You can choose initial conditions for backwards orbits by
clicking
on a location in the view window canvas. This also
resets the current orbit direction from forward to backward. Now
clicking
within the canvas will cause up to 5000 points
along the backward orbit to be displayed. Your backward orbit will
probably rapidly go off to infinity, so dstool will display a message
and stop computing somewhat earlier. On a color monitor, this backward
orbit will automatically have been displayed in the next color of
dstool's palette.
Dstool only remembers one selected point and one orbit
direction. So pressing
or
within the canvas
both sets the orbit direction and replaces any previously selected
point. One of the menu entries under the Options menu button of
the 2-D Image window is Display... which will allow you to
mark this selected point before you change it.