56   double inv2pi = 1.0 / (2.0 * vtkMath::Pi());  in Evaluate()  local
64   Pt[0] = this->A * (1 - v * inv2pi) * cnv * (1 + cu) + this->C * cnv;  in Evaluate()
65   Pt[1] = this->A * (1 - v * inv2pi) * snv * (1 + cu) + this->C * snv;  in Evaluate()
66   Pt[2] = this->B * v * inv2pi + this->A * (1 - v * inv2pi) * su;  in Evaluate()
69   Du[0] = -this->A * (1 - v * inv2pi) * cnv * su;  in Evaluate()
70   Dv[0] = -this->A * inv2pi * cnv * (1 + cu) - this->A *  in Evaluate()
71           (1 - v * inv2pi) * snv * this->N * (1 + cu) - this->C * snv * N;  in Evaluate()
72   Du[1] = -this->A * (1 - v * inv2pi) * snv * su;  in Evaluate()
73   Dv[1] = -this->A * inv2pi * snv * (1 + cu) + this->A *  in Evaluate()
74           (1 - v * inv2pi) * cnv * this->N * (1 + cu) + C * cnv * this->N;  in Evaluate()
75   Du[2] = this->A * (1 - v * inv2pi) * cu;  in Evaluate()
76   Dv[2] = this->B * inv2pi - this->A * inv2pi * su;  in Evaluate()