% discretization

function [yd,y1,y2]=discr(fy,my,t,dis,fil,m)

if fil=1
  yl=0;                               % lower bound of output y
  yu=10;                              % upper bound of output y
  yr=yu-yl;
  y1=yl+dis*yr/m;
  y2=yl+dis*yr/m+yr/m;
  if fy(t)<=y1
    yd=1;
  elseif fy(t)<=y2
    yd=2;
  else 
    yd=3;
else
  yl=-0.15;
  yu=0.15;
  yr=yu-yl;
  y1=yl+dis*yr/m;
  y2=yl+dis*yr/m+yr/m;
  if fy(t)<=y1
    yd=1;
  elseif fy(t)<=2 
    yd=2;
  else
    yd=3;
end