Cannot sample enough valid points. (more)

\[R \cdot \left(2 \cdot \tan^{-1}_* \frac{\sqrt{{\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)}}{\sqrt{1 - \left({\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right)}}\right)\]
R \cdot \left(2 \cdot \tan^{-1}_* \frac{\sqrt{{\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)}}{\sqrt{1 - \left({\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right)}}\right)
double f(double R, double lambda1, double lambda2, double phi1, double phi2) {
        double r8914019 = R;
        double r8914020 = 2.0;
        double r8914021 = phi1;
        double r8914022 = phi2;
        double r8914023 = r8914021 - r8914022;
        double r8914024 = r8914023 / r8914020;
        double r8914025 = sin(r8914024);
        double r8914026 = pow(r8914025, r8914020);
        double r8914027 = cos(r8914021);
        double r8914028 = cos(r8914022);
        double r8914029 = r8914027 * r8914028;
        double r8914030 = lambda1;
        double r8914031 = lambda2;
        double r8914032 = r8914030 - r8914031;
        double r8914033 = r8914032 / r8914020;
        double r8914034 = sin(r8914033);
        double r8914035 = r8914029 * r8914034;
        double r8914036 = r8914035 * r8914034;
        double r8914037 = r8914026 + r8914036;
        double r8914038 = sqrt(r8914037);
        double r8914039 = 1.0;
        double r8914040 = r8914039 - r8914037;
        double r8914041 = sqrt(r8914040);
        double r8914042 = atan2(r8914038, r8914041);
        double r8914043 = r8914020 * r8914042;
        double r8914044 = r8914019 * r8914043;
        return r8914044;
}