plot | (2-2 (x^2+y^2)+(x^2+y^2)^2) (3.5+cos(13 tan^(-1)(x/y)) tanh(1/2 (-x^2-y^2))+cos(3+9 tan^(-1)(x/y)) tanh(1/2 (-x^2-y^2))) | x = -1.25 to 1.25