mode(-1)

mode(1)
// ODE definition
function ydot=lorenz(t,y)
    x=y(1);
    a=[-10,10,0;28,-1,-x;0,x,-8/3];
    ydot=a*y
endfunction

function j=jacobian(t,y)
    x=y(1);yy=y(2);z=y(3);
    j=[-10,10,0;28-z,-1,-x;-yy,x,-8/3]
endfunction

// Integration
y0=[-3;-6;12];t0=0;step=0.01;t1=10;
instants=t0:step:t1;
y=ode(y0,t0,instants,lorenz,jacobian);
//Visualization
clf()
a=gca();a.title.text='Lorenz differential equation';
a.title.font_size=4;
param3d(y(1,:),y(2,:),y(3,:))
