\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \sin \phi_1 \cdot \sin \left(\sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}\lambda_1 + \tan^{-1}_* \frac{\left(\sin theta \cdot \sin delta\right) \cdot \cos \phi_1}{\cos delta - \mathsf{log1p}\left(\mathsf{expm1}\left(\sqrt[3]{{\left(\sin \phi_1 \cdot \sin \left(\sin^{-1} \left(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)\right)}^{3}}\right)\right)}double code(double lambda1, double phi1, double phi2, double delta, double theta) {
return (lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - (sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta)))))))));
}
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
return (lambda1 + atan2(((sin(theta) * sin(delta)) * cos(phi1)), (cos(delta) - log1p(expm1(cbrt(pow((sin(phi1) * sin(asin(((sin(phi1) * cos(delta)) + ((cos(phi1) * sin(delta)) * cos(theta)))))), 3.0)))))));
}



Bits error versus lambda1



Bits error versus phi1



Bits error versus phi2



Bits error versus delta



Bits error versus theta
Results
Initial program 0.1
rmApplied add-cbrt-cube0.2
Applied add-cbrt-cube0.2
Applied cbrt-unprod0.2
Simplified0.2
rmApplied log1p-expm1-u0.2
Final simplification0.2
herbie shell --seed 2020091 +o rules:numerics
(FPCore (lambda1 phi1 phi2 delta theta)
:name "Destination given bearing on a great circle"
:precision binary64
(+ lambda1 (atan2 (* (* (sin theta) (sin delta)) (cos phi1)) (- (cos delta) (* (sin phi1) (sin (asin (+ (* (sin phi1) (cos delta)) (* (* (cos phi1) (sin delta)) (cos theta))))))))))