-Which[m >= 0, ZernikeR[n, m, Sqrt[x^2 + y^2]]*Cos[m ArcTan[x, y]], m < 0, ZernikeR[n, -m, Sqrt[x^2 + y^2]]*Sin[-m ArcTan[x, y]] ]; tmp = Table[ Plot3D[zpoly[x...