> restart;

> read "D:/books/ess/programs/pathDE.mpl";

> f := pathDE( x^2+y^2-1, x, y );

> sol := dsolve( numeric, procedure=f, range=-Pi..Pi, start=0, initial=array([1,0,0,0]), procvars=[xr(s),xi(s),yr(s),yi(s)] );

> plots[odeplot]( sol, [xr(s),yr(s)], scaling=CONSTRAINED, colour=BLACK );

> sol := dsolve( numeric, procedure=f, range=-2*Pi..2*Pi, start=0, initial=array([0,1,sqrt(2),0]), procvars=[xr(s),xi(s),yr(s),yi(s)] );

> P1 := plots[odeplot]( sol, [[s,xr(s)]], linestyle=1, scaling=CONSTRAINED, axes=BOXED, labels=["",""], colour=BLACK):

> P2 := plots[odeplot]( sol, [[s,xi(s)]], linestyle=1, scaling=CONSTRAINED, axes=BOXED, labels=["",""], colour=BLACK):

> P3 := plots[odeplot]( sol, [[s,yr(s)]], linestyle=1, scaling=CONSTRAINED, axes=BOXED, labels=["",""], colour=BLACK):

> P4 := plots[odeplot]( sol, [[s,yi(s)]], linestyle=1, scaling=CONSTRAINED, axes=BOXED, labels=["",""], colour=BLACK):

> plots[display]({P1,P2,P3,P4});

> f2 := pathDE( y^2*exp(-y)-x, x, y );

> sol2 := dsolve( numeric, procedure=f2, range=-4..4, start=0, initial=array([0,0,0,0]), procvars=[xr(s),xi(s),yr(s),yi(s)] );

> plots[odeplot]( sol2, [xr(s),yr(s)], colour=BLACK );