solar.c
static inline double
equation_of_time(double tm)
{
	double l = sun_geometric_mean_longitude(tm);
	double e = earth_orbit_eccentricity(tm);
	double m = sun_geometric_mean_anomaly(tm);
	double y = pow(tan(corrected_mean_ecliptic_obliquity(tm) / 2.0), 2.0);
	double rc = y * sin(2.0 * l);
	rc += (4.0 * y * cos(2.0 * l) - 2.0) * e * sin(m);
	rc -= pow(0.5 * y, 2.0) * sin(4.0 * l);
	rc -= pow(1.25 * e, 2.0) * sin(2.0 * m);
	return 4.0 * degrees(rc);
}
/**
 * Calculates the equation of time, the discrepancy
 * between apparent and mean solar time
 * 
 * @param   tm  The time in Julian Centuries
 * @return      The equation of time, in degrees
 */
Calculates the equation of time, the discrepancy
between apparent and mean solar time

@param   tm  The time in Julian Centuries
@return      The equation of time, in degrees
Calculates the equation of time the discrepancy between apparent and mean solar time @param tm The time in Julian Centuries @return The equation of time in degrees
static inline double
equation_of_time(double tm)
{
	double l = sun_geometric_mean_longitude(tm);
	double e = earth_orbit_eccentricity(tm);
	double m = sun_geometric_mean_anomaly(tm);
	double y = pow(tan(corrected_mean_ecliptic_obliquity(tm) / 2.0), 2.0);
	double rc = y * sin(2.0 * l);
	rc += (4.0 * y * cos(2.0 * l) - 2.0) * e * sin(m);
	rc -= pow(0.5 * y, 2.0) * sin(4.0 * l);
	rc -= pow(1.25 * e, 2.0) * sin(2.0 * m);
	return 4.0 * degrees(rc);
}
static inline double equation_of_time ( double tm ) { double l = sun_geometric_mean_longitude ( tm ) ; double e = earth_orbit_eccentricity ( tm ) ; double m = sun_geometric_mean_anomaly ( tm ) ; double y = pow ( tan ( corrected_mean_ecliptic_obliquity ( tm ) / 2.0 ) , 2.0 ) ; double rc = y * sin ( 2.0 * l ) ; rc += ( 4.0 * y * cos ( 2.0 * l ) - 2.0 ) * e * sin ( m ) ; rc -= pow ( 0.5 * y , 2.0 ) * sin ( 4.0 * l ) ; rc -= pow ( 1.25 * e , 2.0 ) * sin ( 2.0 * m ) ; return 4.0 * degrees ( rc ) ; }
Calculates the equation of time, the discrepancy
 between apparent and mean solar time
Calculates the equation of time the discrepancy between apparent and mean solar time