use super::eect00;

///  Equation of the equinoxes, IAU 2000

///

///  The equation of the equinoxes, compatible with IAU 2000 resolutions,

///  given the nutation in longitude and the mean obliquity.

///

///  This function is part of the International Astronomical Union's

///  SOFA (Standards of Fundamental Astronomy) software collection.

///

///  Status:  canonical model.

///

///  Given:

///  ```

///     date1,date2  double    TT as a 2-part Julian Date (Note 1)

///     epsa         double    mean obliquity (Note 2)

///     dpsi         double    nutation in longitude (Note 3)

///  ```

///  Returned (function value):

///  ```

///  

///                  double    equation of the equinoxes (Note 4)

///  ```

///  Notes:

///

///  1) The TT date date1+date2 is a Julian Date, apportioned in any

///     convenient way between the two arguments.  For example,

///     JD(TT)=2450123.7 could be expressed in any of these ways,

///     among others:

///  ```

///            date1          date2

///

///         2450123.7           0.0       (JD method)

///         2451545.0       -1421.3       (J2000 method)

///         2400000.5       50123.2       (MJD method)

///         2450123.5           0.2       (date & time method)

///  ```

///     The JD method is the most natural and convenient to use in

///     cases where the loss of several decimal digits of resolution

///     is acceptable.  The J2000 method is best matched to the way

///     the argument is handled internally and will deliver the

///     optimum resolution.  The MJD method and the date & time methods

///     are both good compromises between resolution and convenience.

///

///  2) The obliquity, in radians, is mean of date.

///

///  3) The result, which is in radians, operates in the following sense:

///

///        Greenwich apparent ST = GMST + equation of the equinoxes

///

///  4) The result is compatible with the IAU 2000 resolutions.  For

///     further details, see IERS Conventions 2003 and Capitaine et al.

///     (2002).

///

///  Called:

///  ```

///  

///     iauEect00    equation of the equinoxes complementary terms

///  ```

///  References:

///

///     Capitaine, N., Wallace, P.T. and McCarthy, D.D., "Expressions to

///     implement the IAU 2000 definition of UT1", Astronomy &

///     Astrophysics, 406, 1135-1149 (2003)

///

///     McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),

///     IERS Technical Note No. 32, BKG (2004)

pub fn ee00(date1: f64, date2: f64, epsa: f64, dpsi: f64) -> f64 {

    /* Equation of the equinoxes. */

    dpsi * epsa.cos() + eect00(date1, date2)

}