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use super::{pwf06::*, fw2m::*, nut06a::*, };
/// Form the matrix of precession-nutation for a given date (including
/// frame bias), equinox based, IAU 2006 precession and IAU 2000A
/// nutation models.
///
/// Given:
/// date1,date2 double TT as a 2-part Julian Date (Note 1)
///
/// Returned:
/// rbpn double[3][3] bias-precession-nutation matrix (Note 2)
///
/// 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 matrix operates in the sense V(date) = rbpn * V(GCRS), where
/// the p-vector V(date) is with respect to the true equatorial triad
/// of date date1+date2 and the p-vector V(GCRS) is with respect to
/// the Geocentric Celestial Reference System (IAU, 2000).
///
/// Called:
/// eraPfw06 bias-precession F-W angles, IAU 2006
/// eraNut06a nutation, IAU 2006/2000A
/// eraFw2m F-W angles to r-matrix
///
/// Reference:
///
/// Capitaine, N. & Wallace, P.T., 2006, Astron.Astrophys. 450, 855.
///
/// This revision: 2021 May 11
pub fn pnm06a(date1: f64, date2: f64, rbpn: &mut [[f64; 3];3])
{
let mut gamb =0.0; let mut phib =0.0; let mut psib =0.0;
let mut epsa = 0.0; let mut dp =0.0; let mut de = 0.0;
/* Fukushima-Williams angles for frame bias and precession. */
pfw06(date1, date2, &mut gamb, &mut phib, &mut psib, &mut epsa);
/* Nutation components. */
nut06a(date1, date2, &mut dp, &mut de);
/* Equinox based nutation x precession x bias matrix. */
fw2m(gamb, phib, psib + dp, epsa + de, rbpn);
/* Finished. */
}