\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(\sin \lambda_1 \cdot \cos \lambda_2 - \cos \lambda_1 \cdot \sin \lambda_2\right) \cdot \cos \phi_2}{\cos \phi_1 \cdot \sin \phi_2 - \left(\cos \lambda_1 \cdot \left(\left(\sin \phi_1 \cdot \cos \lambda_2\right) \cdot \cos \phi_2\right) + \sqrt[3]{{\left(\sin \lambda_2 \cdot \sin \lambda_1\right)}^{3}} \cdot \left(\sin \phi_1 \cdot \cos \phi_2\right)\right)}double f(double lambda1, double lambda2, double phi1, double phi2) {
double r136759 = lambda1;
double r136760 = lambda2;
double r136761 = r136759 - r136760;
double r136762 = sin(r136761);
double r136763 = phi2;
double r136764 = cos(r136763);
double r136765 = r136762 * r136764;
double r136766 = phi1;
double r136767 = cos(r136766);
double r136768 = sin(r136763);
double r136769 = r136767 * r136768;
double r136770 = sin(r136766);
double r136771 = r136770 * r136764;
double r136772 = cos(r136761);
double r136773 = r136771 * r136772;
double r136774 = r136769 - r136773;
double r136775 = atan2(r136765, r136774);
return r136775;
}
double f(double lambda1, double lambda2, double phi1, double phi2) {
double r136776 = lambda1;
double r136777 = sin(r136776);
double r136778 = lambda2;
double r136779 = cos(r136778);
double r136780 = r136777 * r136779;
double r136781 = cos(r136776);
double r136782 = sin(r136778);
double r136783 = r136781 * r136782;
double r136784 = r136780 - r136783;
double r136785 = phi2;
double r136786 = cos(r136785);
double r136787 = r136784 * r136786;
double r136788 = phi1;
double r136789 = cos(r136788);
double r136790 = sin(r136785);
double r136791 = r136789 * r136790;
double r136792 = sin(r136788);
double r136793 = r136792 * r136779;
double r136794 = r136793 * r136786;
double r136795 = r136781 * r136794;
double r136796 = r136782 * r136777;
double r136797 = 3.0;
double r136798 = pow(r136796, r136797);
double r136799 = cbrt(r136798);
double r136800 = r136792 * r136786;
double r136801 = r136799 * r136800;
double r136802 = r136795 + r136801;
double r136803 = r136791 - r136802;
double r136804 = atan2(r136787, r136803);
return r136804;
}



Bits error versus lambda1



Bits error versus lambda2



Bits error versus phi1



Bits error versus phi2
Results
Initial program 12.9
rmApplied sin-diff6.7
rmApplied cos-diff0.2
Applied distribute-lft-in0.2
Simplified0.2
Simplified0.2
rmApplied associate-*l*0.2
Simplified0.2
rmApplied add-cbrt-cube0.2
Applied add-cbrt-cube0.2
Applied cbrt-unprod0.2
Simplified0.2
Final simplification0.2
herbie shell --seed 2019351
(FPCore (lambda1 lambda2 phi1 phi2)
:name "Bearing on a great circle"
:precision binary64
(atan2 (* (sin (- lambda1 lambda2)) (cos phi2)) (- (* (cos phi1) (sin phi2)) (* (* (sin phi1) (cos phi2)) (cos (- lambda1 lambda2))))))