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 r1121380 = R;
        double r1121381 = 2.0;
        double r1121382 = phi1;
        double r1121383 = phi2;
        double r1121384 = r1121382 - r1121383;
        double r1121385 = r1121384 / r1121381;
        double r1121386 = sin(r1121385);
        double r1121387 = pow(r1121386, r1121381);
        double r1121388 = cos(r1121382);
        double r1121389 = cos(r1121383);
        double r1121390 = r1121388 * r1121389;
        double r1121391 = lambda1;
        double r1121392 = lambda2;
        double r1121393 = r1121391 - r1121392;
        double r1121394 = r1121393 / r1121381;
        double r1121395 = sin(r1121394);
        double r1121396 = r1121390 * r1121395;
        double r1121397 = r1121396 * r1121395;
        double r1121398 = r1121387 + r1121397;
        double r1121399 = sqrt(r1121398);
        double r1121400 = 1.0;
        double r1121401 = r1121400 - r1121398;
        double r1121402 = sqrt(r1121401);
        double r1121403 = atan2(r1121399, r1121402);
        double r1121404 = r1121381 * r1121403;
        double r1121405 = r1121380 * r1121404;
        return r1121405;
}