To begin, enter the necessary information into the fields below:

  the bounds for the plot window

   and , the right-hand sides of the autonomous ODEs  and

  one equilibrium (critical) point as a list , and multiple such points in a sequence

  bounds for , the independent variable of the ODEs, and hence, the parameter along orbits (trajectories or paths)

Click the Enter Data button to obtain a direction field and all entered equilibrium (critical) points.

Click on the plot area and select the Click and Drag Manipulator ( ) from the Plot menu or plotting toolbar.  Then click anywhere in the direction field to create a phase portrait through that point.

The Erase Phase Portrait button erases all orbits and field arrows.  The Clear All button clears every field in the template.