\tan^{-1}_* \frac{\sin \left(\lambda_1 - \lambda_2\right) \cdot \cos \phi_2}{\cos \phi_1 \cdot \sin \phi_2 - \left(\sin \phi_1 \cdot \cos \phi_2\right) \cdot \cos \left(\lambda_1 - \lambda_2\right)}\tan^{-1}_* \frac{\left(\cos \lambda_2 \cdot \sin \lambda_1 - \cos \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_2}{\sin \phi_2 \cdot \cos \phi_1 - \left(\left(\cos \lambda_2 \cdot \cos \lambda_1\right) \cdot \left(\cos \phi_2 \cdot \sin \phi_1\right) + \left(\sqrt[3]{\sin \lambda_2 \cdot \sin \lambda_1} \cdot \left(\sqrt[3]{\sin \lambda_2 \cdot \sin \lambda_1} \cdot \sqrt[3]{\sin \lambda_2 \cdot \sin \lambda_1}\right)\right) \cdot \left(\cos \phi_2 \cdot \sin \phi_1\right)\right)}double f(double lambda1, double lambda2, double phi1, double phi2) {
double r5107257 = lambda1;
double r5107258 = lambda2;
double r5107259 = r5107257 - r5107258;
double r5107260 = sin(r5107259);
double r5107261 = phi2;
double r5107262 = cos(r5107261);
double r5107263 = r5107260 * r5107262;
double r5107264 = phi1;
double r5107265 = cos(r5107264);
double r5107266 = sin(r5107261);
double r5107267 = r5107265 * r5107266;
double r5107268 = sin(r5107264);
double r5107269 = r5107268 * r5107262;
double r5107270 = cos(r5107259);
double r5107271 = r5107269 * r5107270;
double r5107272 = r5107267 - r5107271;
double r5107273 = atan2(r5107263, r5107272);
return r5107273;
}
double f(double lambda1, double lambda2, double phi1, double phi2) {
double r5107274 = lambda2;
double r5107275 = cos(r5107274);
double r5107276 = lambda1;
double r5107277 = sin(r5107276);
double r5107278 = r5107275 * r5107277;
double r5107279 = cos(r5107276);
double r5107280 = sin(r5107274);
double r5107281 = r5107279 * r5107280;
double r5107282 = r5107278 - r5107281;
double r5107283 = phi2;
double r5107284 = cos(r5107283);
double r5107285 = r5107282 * r5107284;
double r5107286 = sin(r5107283);
double r5107287 = phi1;
double r5107288 = cos(r5107287);
double r5107289 = r5107286 * r5107288;
double r5107290 = r5107275 * r5107279;
double r5107291 = sin(r5107287);
double r5107292 = r5107284 * r5107291;
double r5107293 = r5107290 * r5107292;
double r5107294 = r5107280 * r5107277;
double r5107295 = cbrt(r5107294);
double r5107296 = r5107295 * r5107295;
double r5107297 = r5107295 * r5107296;
double r5107298 = r5107297 * r5107292;
double r5107299 = r5107293 + r5107298;
double r5107300 = r5107289 - r5107299;
double r5107301 = atan2(r5107285, r5107300);
return r5107301;
}



Bits error versus lambda1



Bits error versus lambda2



Bits error versus phi1



Bits error versus phi2
Results
Initial program 13.2
rmApplied sin-diff6.7
rmApplied cos-diff0.2
Applied distribute-rgt-in0.2
rmApplied add-cube-cbrt0.2
Final simplification0.2
herbie shell --seed 2019151
(FPCore (lambda1 lambda2 phi1 phi2)
:name "Bearing on a great circle"
(atan2 (* (sin (- lambda1 lambda2)) (cos phi2)) (- (* (cos phi1) (sin phi2)) (* (* (sin phi1) (cos phi2)) (cos (- lambda1 lambda2))))))