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 r15164026 = R;
        double r15164027 = 2.0;
        double r15164028 = phi1;
        double r15164029 = phi2;
        double r15164030 = r15164028 - r15164029;
        double r15164031 = r15164030 / r15164027;
        double r15164032 = sin(r15164031);
        double r15164033 = pow(r15164032, r15164027);
        double r15164034 = cos(r15164028);
        double r15164035 = cos(r15164029);
        double r15164036 = r15164034 * r15164035;
        double r15164037 = lambda1;
        double r15164038 = lambda2;
        double r15164039 = r15164037 - r15164038;
        double r15164040 = r15164039 / r15164027;
        double r15164041 = sin(r15164040);
        double r15164042 = r15164036 * r15164041;
        double r15164043 = r15164042 * r15164041;
        double r15164044 = r15164033 + r15164043;
        double r15164045 = sqrt(r15164044);
        double r15164046 = 1.0;
        double r15164047 = r15164046 - r15164044;
        double r15164048 = sqrt(r15164047);
        double r15164049 = atan2(r15164045, r15164048);
        double r15164050 = r15164027 * r15164049;
        double r15164051 = r15164026 * r15164050;
        return r15164051;
}