An example of implicit definition of y as a function of x. f(x,y) = x**3 + y**3 - 2*x*y**2 - y*x**2 + 1 Equation: f(x,y) = 0 The simpliest algorithm I could think of to plot this curve is: Color a point (x,y) &thinsp red &ensp &ensp &thinsp if f(x,y)<0 &thinsp green &ensp if f(x,y)>0 Then the boundary between the red and green region is the curve f(x,y)=0. The picture on the right is a rectangle with x,y coordinates between -3 and 3. Python source code