# An example. Place your definition in the following line:
f(x,y) = y - x**2 / tan(y)

f1(x,y) = +(0.0138866) +(-0.517588)*x +(1.25336)*y
f2(x,y) = +(2.19909) +(0.669282)*x +(3.5439)*y +(-1.36924)*x**2 +(-0.94907)*x*y +(-1.26662)*y**2
f3(x,y) = +(2.58419) +(1.04546)*x +(2.3387)*y +(-3.03105)*x**2 +(-4.78246)*x*y +(-0.96096)*y**2 +(0.699026)*x**3 +(4.1775)*x**2*y +(-2.03621)*x*y**2 +(0.693941)*y**3

set dgrid3d 100,100
set isosample 100
set contour base
set cntrparam levels discrete -1,0.0,1
#set cntrparam bspline
unset surface
set table 'z.curve.dat'
splot[-2:3][-2:3] 'data2'#,f1(x,y),f2(x,y),f3(x,y)
unset table
plot 'z.curve.dat' w l


#plot [-2:3][-2:3] 'data' us 1:2:3 pt 2 lc variable title 'data','./z.curve.dat' us 1:2:(abs($3)*2) with lines lc variable title 'decision boundary'
