#y = x*x/a/a - z*z/b/b

vertices = dimension1:320 dimension2:320

u = from (-5) to (5) dimension1
v = from (-5) to (5) dimension2

a = rand2(0.5, 2)
b = rand2(0.5, 2)

x = a*(u + v)
z = b*(u - v)
y = 2*u*v