\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(\sin \phi_1 \cdot \cos delta + \left(\cos \phi_1 \cdot \sin delta\right) \cdot \cos theta\right)\right)}\right)}double f(double lambda1, double phi1, double __attribute__((unused)) phi2, double delta, double theta) {
double r94002 = lambda1;
double r94003 = theta;
double r94004 = sin(r94003);
double r94005 = delta;
double r94006 = sin(r94005);
double r94007 = r94004 * r94006;
double r94008 = phi1;
double r94009 = cos(r94008);
double r94010 = r94007 * r94009;
double r94011 = cos(r94005);
double r94012 = sin(r94008);
double r94013 = r94012 * r94011;
double r94014 = r94009 * r94006;
double r94015 = cos(r94003);
double r94016 = r94014 * r94015;
double r94017 = r94013 + r94016;
double r94018 = asin(r94017);
double r94019 = sin(r94018);
double r94020 = r94012 * r94019;
double r94021 = r94011 - r94020;
double r94022 = atan2(r94010, r94021);
double r94023 = r94002 + r94022;
return r94023;
}
double f(double lambda1, double phi1, double __attribute__((unused)) phi2, double delta, double theta) {
double r94024 = lambda1;
double r94025 = theta;
double r94026 = sin(r94025);
double r94027 = delta;
double r94028 = sin(r94027);
double r94029 = r94026 * r94028;
double r94030 = phi1;
double r94031 = cos(r94030);
double r94032 = r94029 * r94031;
double r94033 = cos(r94027);
double r94034 = sin(r94030);
double r94035 = r94034 * r94033;
double r94036 = r94031 * r94028;
double r94037 = cos(r94025);
double r94038 = r94036 * r94037;
double r94039 = r94035 + r94038;
double r94040 = asin(r94039);
double r94041 = sin(r94040);
double r94042 = r94034 * r94041;
double r94043 = r94033 - r94042;
double r94044 = exp(r94043);
double r94045 = log(r94044);
double r94046 = atan2(r94032, r94045);
double r94047 = r94024 + r94046;
return r94047;
}



Bits error versus lambda1



Bits error versus phi1



Bits error versus phi2



Bits error versus delta



Bits error versus theta
Results
Initial program 0.2
rmApplied add-log-exp0.2
Applied add-log-exp0.2
Applied diff-log0.2
Simplified0.2
Final simplification0.2
herbie shell --seed 2019354
(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))))))))))