This simulation shows the potential surface of the vector field, with particles following the velocity vectors. [br][br]Enter an arbitrary potential function in the box [b]Potential[/b]. Try for example:[br][list][*]-(sqrt(x^2 + y^2) + 1 / sqrt(x^2 + y^2)) cos(atan2(y,x))[br][/*][*]ln(sqrt((x + 1)^2 + y^2)) - ln(sqrt((x - 1)^2 + y^2))[/*][*]1/sqrt(x^2+y^2)[br][/*][*]sqrt(x^2+y^2)[/*][*]arctan2(y,x)[/*][*]x^2-y^2[/*][*]x-1/2y^2[/*][*]-1/x^2[/*][*]abs(x)[br][/*][*]-x[br][/*][/list]