x-nullclines
Here we illustrate first for the -nullclines of the competing species example from the text:
> xNULLeqn := factor( rhs(ode1) ) = 0 ;
Thus, the -nullcline consists of the two lines and . Here is how these might be plotted:
> xNULL1 := plot( [ 0, y, y=-2..4 ], color=GREEN ):
> xNULL2 := plot( 2-x, x=-2..4, color=GREEN ):
> xNULLplot := display( [ xNULL1, xNULL2 ], axes=BOXED ):
> xNULLplot;
>