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//
// GENERATED FILE
//
use super::*;
use crate::SpiceContext;
use f2rust_std::*;
/// Rectangular to spherical coordinates
///
/// Convert from rectangular coordinates to spherical coordinates.
///
/// # Brief I/O
///
/// ```text
/// VARIABLE I/O DESCRIPTION
/// -------- --- --------------------------------------------------
/// RECTAN I Rectangular coordinates of a point.
/// R O Distance of the point from the origin.
/// COLAT O Angle of the point from the Z-axis (radians)
/// SLON O Longitude of the point (radians).
/// ```
///
/// # Detailed Input
///
/// ```text
/// RECTAN are the rectangular coordinates of a point.
/// ```
///
/// # Detailed Output
///
/// ```text
/// R is the distance of the point from the origin.
///
/// COLAT is the angle between the point and the positive Z-axis in
/// radians. The range of COLAT is [0, pi].
///
/// SLON is the longitude of the point in radians. This is the
/// angle between the positive X-axis and the orthogonal
/// projection of the point onto the XY plane. SLON increases
/// in the counterclockwise sense about the positive Z-axis.
/// The range of SLON is [-pi, pi].
/// ```
///
/// # Exceptions
///
/// ```text
/// Error free.
/// ```
///
/// # Particulars
///
/// ```text
/// This routine returns the spherical coordinates of a point
/// whose position is input in rectangular coordinates.
///
/// Spherical coordinates are defined by a distance from a central
/// reference point, an angle from a reference meridian, and an angle
/// from the z-axis.
/// ```
///
/// # Examples
///
/// ```text
/// The numerical results shown for these examples may differ across
/// platforms. The results depend on the SPICE kernels used as
/// input, the compiler and supporting libraries, and the machine
/// specific arithmetic implementation.
///
/// 1) Compute the spherical coordinates of the position of the Moon
/// as seen from the Earth, and convert them to rectangular
/// coordinates.
///
/// Use the meta-kernel shown below to load the required SPICE
/// kernels.
///
///
/// KPL/MK
///
/// File name: recsph_ex1.tm
///
/// This meta-kernel is intended to support operation of SPICE
/// example programs. The kernels shown here should not be
/// assumed to contain adequate or correct versions of data
/// required by SPICE-based user applications.
///
/// In order for an application to use this meta-kernel, the
/// kernels referenced here must be present in the user's
/// current working directory.
///
/// The names and contents of the kernels referenced
/// by this meta-kernel are as follows:
///
/// File name Contents
/// --------- --------
/// de421.bsp Planetary ephemeris
/// naif0012.tls Leapseconds
///
///
/// \begindata
///
/// KERNELS_TO_LOAD = ( 'de421.bsp',
/// 'naif0012.tls' )
///
/// \begintext
///
/// End of meta-kernel
///
///
/// Example code begins here.
///
///
/// PROGRAM RECSPH_EX1
/// IMPLICIT NONE
///
/// C
/// C SPICELIB functions
/// C
/// DOUBLE PRECISION DPR
///
/// C
/// C Local parameters
/// C
/// CHARACTER*(*) FMT1
/// PARAMETER ( FMT1 = '(A,F20.8)' )
///
/// C
/// C Local variables
/// C
/// DOUBLE PRECISION CLON
/// DOUBLE PRECISION COLAT
/// DOUBLE PRECISION ET
/// DOUBLE PRECISION LT
/// DOUBLE PRECISION POS ( 3 )
/// DOUBLE PRECISION R
/// DOUBLE PRECISION RADIUS
/// DOUBLE PRECISION RECTAN ( 3 )
/// DOUBLE PRECISION SLON
/// DOUBLE PRECISION Z
///
/// C
/// C Load SPK and LSK kernels, use a meta kernel for
/// C convenience.
/// C
/// CALL FURNSH ( 'recsph_ex1.tm' )
///
/// C
/// C Look up the geometric state of the Moon as seen from
/// C the Earth at 2017 Mar 20, relative to the J2000
/// C reference frame.
/// C
/// CALL STR2ET ( '2017 Mar 20', ET )
///
/// CALL SPKPOS ( 'Moon', ET, 'J2000', 'NONE',
/// . 'Earth', POS, LT )
///
/// C
/// C Convert the position vector POS to spherical
/// C coordinates.
/// C
/// CALL RECSPH ( POS, RADIUS, COLAT, SLON )
///
/// C
/// C Convert the spherical coordinates to rectangular.
/// C
/// CALL SPHREC ( RADIUS, COLAT, SLON, RECTAN )
///
///
/// WRITE(*,*) ' '
/// WRITE(*,*) 'Original rectangular coordinates:'
/// WRITE(*,*) ' '
/// WRITE(*,FMT1) ' X (km): ', POS(1)
/// WRITE(*,FMT1) ' Y (km): ', POS(2)
/// WRITE(*,FMT1) ' Z (km): ', POS(3)
/// WRITE(*,*) ' '
/// WRITE(*,*) 'Spherical coordinates:'
/// WRITE(*,*) ' '
/// WRITE(*,FMT1) ' Radius (km): ', RADIUS
/// WRITE(*,FMT1) ' Colatitude (deg): ', COLAT*DPR()
/// WRITE(*,FMT1) ' Longitude (deg): ', SLON*DPR()
/// WRITE(*,*) ' '
/// WRITE(*,*) 'Rectangular coordinates from SPHREC:'
/// WRITE(*,*) ' '
/// WRITE(*,FMT1) ' X (km): ', RECTAN(1)
/// WRITE(*,FMT1) ' Y (km): ', RECTAN(2)
/// WRITE(*,FMT1) ' Z (km): ', RECTAN(3)
/// WRITE(*,*) ' '
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// Original rectangular coordinates:
///
/// X (km): -55658.44323296
/// Y (km): -379226.32931475
/// Z (km): -126505.93063865
///
/// Spherical coordinates:
///
/// Radius (km): 403626.33912495
/// Colatitude (deg): 108.26566077
/// Longitude (deg): -98.34959789
///
/// Rectangular coordinates from SPHREC:
///
/// X (km): -55658.44323296
/// Y (km): -379226.32931475
/// Z (km): -126505.93063865
///
///
/// 2) Create a table showing a variety of rectangular coordinates
/// and the corresponding spherical coordinates.
///
/// Corresponding rectangular and spherical coordinates are
/// listed to three decimal places. Output angles in degrees.
///
///
/// Example code begins here.
///
///
/// PROGRAM RECSPH_EX2
/// IMPLICIT NONE
///
/// C
/// C SPICELIB functions
/// C
/// DOUBLE PRECISION DPR
///
/// C
/// C Local parameters.
/// C
/// INTEGER NREC
/// PARAMETER ( NREC = 11 )
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION COLAT
/// DOUBLE PRECISION RADIUS
/// DOUBLE PRECISION RECTAN ( 3, NREC )
/// DOUBLE PRECISION SLON
///
/// INTEGER I
/// INTEGER J
///
/// C
/// C Define the input rectangular coordinates.
/// C
/// DATA RECTAN /
/// . 0.D0, 0.D0, 0.D0,
/// . 1.D0, 0.D0, 0.D0,
/// . 0.D0, 1.D0, 0.D0,
/// . 0.D0, 0.D0, 1.D0,
/// . -1.D0, 0.D0, 0.D0,
/// . 0.D0, -1.D0, 0.D0,
/// . 0.D0, 0.D0, -1.D0,
/// . 1.D0, 1.D0, 0.D0,
/// . 1.D0, 0.D0, 1.D0,
/// . 0.D0, 1.D0, 1.D0,
/// . 1.D0, 1.D0, 1.D0 /
///
/// C
/// C Print the banner.
/// C
/// WRITE(*,*) ' RECT(1) RECT(2) RECT(3) '
/// . // ' RADIUS COLAT SLON '
/// WRITE(*,*) ' ------- ------- ------- '
/// . // ' ------- ------- ------- '
///
/// C
/// C Do the conversion. Output angles in degrees.
/// C
/// DO I = 1, NREC
///
/// CALL RECSPH( RECTAN(1,I), RADIUS, COLAT, SLON )
///
/// WRITE (*,'(6F9.3)') ( RECTAN(J,I), J=1,3 ),
/// . RADIUS, COLAT * DPR(),
/// . SLON * DPR()
///
/// END DO
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// RECT(1) RECT(2) RECT(3) RADIUS COLAT SLON
/// ------- ------- ------- ------- ------- -------
/// 0.000 0.000 0.000 0.000 0.000 0.000
/// 1.000 0.000 0.000 1.000 90.000 0.000
/// 0.000 1.000 0.000 1.000 90.000 90.000
/// 0.000 0.000 1.000 1.000 0.000 0.000
/// -1.000 0.000 0.000 1.000 90.000 180.000
/// 0.000 -1.000 0.000 1.000 90.000 -90.000
/// 0.000 0.000 -1.000 1.000 180.000 0.000
/// 1.000 1.000 0.000 1.414 90.000 45.000
/// 1.000 0.000 1.000 1.414 45.000 0.000
/// 0.000 1.000 1.000 1.414 45.000 90.000
/// 1.000 1.000 1.000 1.732 54.736 45.000
/// ```
///
/// # Author and Institution
///
/// ```text
/// N.J. Bachman (JPL)
/// J. Diaz del Rio (ODC Space)
/// B.V. Semenov (JPL)
/// W.L. Taber (JPL)
/// ```
///
/// # Version
///
/// ```text
/// - SPICELIB Version 1.1.0, 06-JUL-2021 (JDR)
///
/// Changed the argument name LONG to SLON for consistency with
/// other routines.
///
/// Added IMPLICIT NONE statement.
///
/// Edited the header to comply with NAIF standard. Added complete
/// code examples. Removed unnecessary $Revisions section.
///
/// - SPICELIB Version 1.0.3, 26-JUL-2016 (BVS)
///
/// Minor headers edits.
///
/// - SPICELIB Version 1.0.2, 07-JAN-2002 (NJB)
///
/// Fixed description of SLON in $Brief_I/O and Detailed_I/O
/// header sections.
///
/// - SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)
///
/// Comment section for permuted index source lines was added
/// following the header.
///
/// - SPICELIB Version 1.0.0, 31-JAN-1990 (WLT)
/// ```
pub fn recsph(rectan: &[f64; 3], r: &mut f64, colat: &mut f64, slon: &mut f64) {
RECSPH(rectan, r, colat, slon);
}
//$Procedure RECSPH ( Rectangular to spherical coordinates )
pub fn RECSPH(RECTAN: &[f64], R: &mut f64, COLAT: &mut f64, SLON: &mut f64) {
let RECTAN = DummyArray::new(RECTAN, 1..=3);
let mut X: f64 = 0.0;
let mut Y: f64 = 0.0;
let mut Z: f64 = 0.0;
let mut BIG: f64 = 0.0;
//
// Store rectangular coordinates in temporary variables
//
BIG = intrinsics::DMAX1(&[
f64::abs(RECTAN[1]),
f64::abs(RECTAN[2]),
f64::abs(RECTAN[3]),
]);
if (BIG > 0 as f64) {
X = (RECTAN[1] / BIG);
Y = (RECTAN[2] / BIG);
Z = (RECTAN[3] / BIG);
*R = (BIG * f64::sqrt((((X * X) + (Y * Y)) + (Z * Z))));
*COLAT = f64::atan2(f64::sqrt(((X * X) + (Y * Y))), Z);
X = RECTAN[1];
Y = RECTAN[2];
if ((X == 0.0) && (Y == 0.0)) {
*SLON = 0.0;
} else {
*SLON = f64::atan2(Y, X);
}
} else {
*R = 0.0;
*COLAT = 0.0;
*SLON = 0.0;
}
}