function M=att(n)


a=1.5;
b=1.84;
c=-2;
d=-1.8;

x(1)=0;
x(2)=0;
nul=1000;

for nul=1:1000
   x(1)=sin(a*x(2))-cos(b*x(1));
   x(2)=sin(c*x(1))-cos(d*x(2));
   nul=nul-1;
end

res=2048;
M = zeros(res,res,3);
y = x;
oldy1 = x;
oldy2 = x;

for i=1:n
      
      oldy2 = oldy1;
      oldy1 = y;
      y(1) = sin(a*x(2))-cos(b*x(1));
      y(2) = sin(c*x(1))-cos(d*x(2));

      diff = y-x;
      curv = (y-2*oldy1+oldy2)/2;

      x = y;

      posi = 1+min(res-1, max(0, round((x(1) + 2)/4.1*res)));
      posj = 1+min(res-1, max(0, round((x(2) + 2)/4.1*res)));

      M(posi, posj,1) = M(posi,posj,1) + abs(diff(1));
      M(posi, posj,2) = M(posi,posj,2) + abs(diff(2));
      M(posi, posj,3) = M(posi,posj,3) + norm(curv);
end

max(max(M))