DsTool Help Page

What is DsTool?

DsTool (short for Dynamical Systems TOOLkit) is a large public-domain software package for researchers and educators studying dynamical systems (both differential equations and discrete time systems). It provides the user with an interactive graphical interface for computations in dynamical systems and visualization of resulting geometric structures.

DsTool was designed on SUN workstations, but has also been installed on other workstations, including the SGI/IRIS workstations at the Geometry Center. DsTool is not installed on the NeXT computers.

How to quit DsTool

To quit DsTool,

Helpful hint

Whenever the expression "press the button marked..." is used in this document, it means "move the mouse so that the cursor is pointing to the button marked.... Then click the left mouse button."

Computing a trajectory

The largest window in DsTool is called the TwoD View Window. This is where trajectories are displayed.

You can initiate the computation of a trajectory forward in time in two ways:

A trajectory can be continued from the last point calculated by Trajectory calculations can be initiated in backwards time by

Stopping when an event occurs

Sometimes you want to compute a trajectory until a certain event occurs. For this example, we will assume that you want to stop a trajectory every time that the velocity, v, of a particle is zero. That is, we want to stop whenever v=0. To return to the default stopping mode,

Clearing old data

When the screen becomes cluttered, you can erase the plotted trajectories by

Zooming in and out

Sometimes you may want to change the range of the window in which trajectories are displayed. This can be done in two ways: After zooming in or out you may want to return the viewing range of the TwoD View Window to its default values. To do this:

How to refresh the screen

After changing the view ranges of the TwoD View Window (and at other times) you will want to redraw previously computed trajectories. To do this

How to print

Once you have data in the a TwoD View Window, you can print this data.

How to change models

To select a new dynamical system:

How to load a data file

To load a file into DsTool:

The Main (Command) Panel

The Command Panel is used to change models and to call up other DsTool panels and features. For easy identification, here is a picture of the Command Panel.

command panel

The Selected Point Panel

The Selected Point Panel is used to type in initial conditions for a dynamical system. For easy identification, here is a picture of the Selected Point Panel.

selected panel

The Orbits Panel

The Orbits Panel is used to control the computation of the trajectory of a dynamical system. For easy identification, here is a picture of the Orbits Panel.

orbits panel

The 2D View Panel

The 2D View Panel is used to display the computed trajectories for the dynamical system being studied. For easy identification, here is a picture of the 2D View Panel.

2D view panel

Frederick J. Wicklin <fjw@geom.umn.edu>
Last modified: Wed Sep 20 08:30:27 1995