for i=1:30
   for j=1:30
     x=0.1*i;
     y=0.1*j;
     z(i,j)=sin(2*x*y);
   end
end
mesh (z)

 print -deps -f FILE.eps

# new type

for i=1:30
   for j=1:30
     x(i)=0.1*i;
     y(j)=0.1*j;
     z(i,j)=sin(2*x(i)*y(j));
   end
end
mesh (x,y,z)