Direction Field

> DIRplot := DEplot( MODEL, VAR, DOMAIN, WINDOW, arrows = MEDIUM,

> title = `Figure 2.32` ):

> DIRplot;

>

> display( [NULLplot,DIRplot], title="Nullclines and Direction Field for Competing Species Model" );

Observe how the nullclines fit with the direction field. Across each x-nullcline (green) the direction field is vertical (changes from left to right or vice versa) and across each y-nullcline (blue) the direction field is horizontal (changes from up to down or vice versa).

>