Section 7.5, Example 3

> with(linalg):with(plots):with(plottools):with(DEtools):

Warning, the name arrow has been redefined

Warning, the name arrow has been redefined

Warning, the names adjoint and translate have been redefined

> A:=matrix([[0,1,1],[1,0,1],[1,1,0]]);

> eigenvectors(A);

> n:=crossprod(vector([-1, 1, 0]),vector([-1, 0, 1]));

> espace1:=plot3d(-x-y,x=-5..5,y=-5..5,view=-5..5,color=blue):

> espace2:=line([-5,-5,-5], [5,5,5],color=green,thickness=3 ):

> curves:=DEplot3d(
[D(x)(t)=y(t)+z(t),D(y)(t)=x(t)+z(t),D(z)(t)=x(t)+y(t)],
[x(t),y(t),z(t)],t=0..5,
[[x(0)=5,y(0)=0,z(0)=-5],[x(0)=5,y(0)=-5,z(0)=0],
[x(0)=0,y(0)=-5,z(0)=5],[x(0)=0,y(0)=5,z(0)=-5],
[x(0)=-5,y(0)=0,z(0)=5.5],[x(0)=-5,y(0)=0,z(0)=4.5],
[x(0)=5.5,y(0)=0,z(0)=-5]],
x=-5..5,y=-5..5,view=-5..5,
linecolor=red,
thickness=3,stepsize=0.1):

> display(espace1,espace2,curves);

>