function z = lrnz(t,x)
%   lrnz(t,x): Lorentz Eq.
% x(1:3) is a column vector of 3 components

%sig=10;b=8/3;r=28;              % the coefficents, chaotic
sig=10;b=3;r=20;						%non-chaotic
a=[-sig sig 0                   % the matrix
r -1 -x(1)
x(2) 0 -b];
z=a*x;                          % Output