function [p, dim, gam] = plant (t);
if nargin < 1,
  disp ('usage:  [p, dim, gam] = plant (t)');
  return;
end

a0 = [0 0 -25; 0 0 0; 0 1 0];
a = a0 - [[0.013 0.020; 0.003 0.022; 0 0] [0.2; 0.055; 0]*t]*t;
g = ss (a, [-25; -18; 0], [0 0 1], 0);
del = ss (-40, 4*sqrt(5), 4*sqrt(5), -1);
p = [1 0 0; 0 0 1; 1 0 0] +  [1; 0; 1]*(2+t/4)*g*del*[0 1 1];

dim = [1 1];
gam = 3.19;

