\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}{\log \left(e^{\cos delta - \sin \phi_1 \cdot \sin \left(\sin^{-1} \left(\cos delta \cdot \sin \phi_1 + \cos \phi_1 \cdot \left(\sin delta \cdot \cos theta\right)\right)\right)}\right)}(FPCore (lambda1 phi1 phi2 delta theta)
: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))))))))))(FPCore (lambda1 phi1 phi2 delta theta)
:precision binary64
(+
lambda1
(atan2
(* (* (sin theta) (sin delta)) (cos phi1))
(log
(exp
(-
(cos delta)
(*
(sin phi1)
(sin
(asin
(+
(* (cos delta) (sin phi1))
(* (cos phi1) (* (sin delta) (cos theta)))))))))))))double code(double lambda1, double phi1, double phi2, double delta, double theta) {
return ((double) (lambda1 + ((double) atan2(((double) (((double) (((double) sin(theta)) * ((double) sin(delta)))) * ((double) cos(phi1)))), ((double) (((double) cos(delta)) - ((double) (((double) sin(phi1)) * ((double) sin(((double) asin(((double) (((double) (((double) sin(phi1)) * ((double) cos(delta)))) + ((double) (((double) (((double) cos(phi1)) * ((double) sin(delta)))) * ((double) cos(theta))))))))))))))))));
}
double code(double lambda1, double phi1, double phi2, double delta, double theta) {
return ((double) (lambda1 + ((double) atan2(((double) (((double) (((double) sin(theta)) * ((double) sin(delta)))) * ((double) cos(phi1)))), ((double) log(((double) exp(((double) (((double) cos(delta)) - ((double) (((double) sin(phi1)) * ((double) sin(((double) asin(((double) (((double) (((double) cos(delta)) * ((double) sin(phi1)))) + ((double) (((double) cos(phi1)) * ((double) (((double) sin(delta)) * ((double) cos(theta))))))))))))))))))))))));
}



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-log-exp0.2
Applied add-log-exp0.2
Applied diff-log0.2
Simplified0.2
Final simplification0.2
herbie shell --seed 2020198
(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))))))))))