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//
// GENERATED FILE
//
use super::*;
use crate::SpiceContext;
use f2rust_std::*;
/// Unit vector and norm, 3 dimensional
///
/// Normalize a double precision 3-vector and return its magnitude.
///
/// # Brief I/O
///
/// ```text
/// VARIABLE I/O DESCRIPTION
/// -------- --- --------------------------------------------------
/// V1 I Vector to be normalized.
/// VOUT O Unit vector V1 / |V1|.
/// VMAG O Magnitude of V1, i.e. |V1|.
/// ```
///
/// # Detailed Input
///
/// ```text
/// V1 is an arbitrary 3-vector, including the
/// zero vector.
/// ```
///
/// # Detailed Output
///
/// ```text
/// VOUT is the unit vector in the direction of V1. If V1 is
/// the zero vector, then VOUT will also be the zero
/// vector.
///
/// VMAG is the magnitude of V1.
/// ```
///
/// # Exceptions
///
/// ```text
/// Error free.
/// ```
///
/// # Particulars
///
/// ```text
/// UNORM references a function called VNORM (which itself is
/// numerically stable) to calculate the norm of the input vector V1.
/// If the norm is equal to zero, then each component of the output
/// vector VOUT is set to zero. Otherwise, VOUT is calculated by
/// dividing V1 by the norm.
/// ```
///
/// # Examples
///
/// ```text
/// The numerical results shown for this example 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) Define a set of vectors and compute their corresponding unit
/// vector and magnitudes.
///
///
/// Example code begins here.
///
///
/// PROGRAM UNORM_EX1
/// IMPLICIT NONE
///
/// C
/// C Local parameters.
/// C
/// INTEGER SETSIZ
/// PARAMETER ( SETSIZ = 2 )
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION VMAG
/// DOUBLE PRECISION SETA ( 3, SETSIZ )
/// DOUBLE PRECISION VOUT ( 3 )
///
/// INTEGER I
/// INTEGER J
///
/// C
/// C Define the vector set.
/// C
/// DATA SETA / 5.D0, 12.D0, 0.D0,
/// . 1.D-7, 2.D-7, 2.D-7 /
///
/// C
/// C Calculate the unit vectors and magnitudes.
/// C
/// DO I=1, SETSIZ
///
/// CALL UNORM ( SETA(1,I), VOUT, VMAG )
///
/// WRITE(*,'(A,3F13.8)') 'Vector : ',
/// . ( SETA(J,I), J=1, 3 )
/// WRITE(*,'(A,3F13.8)') 'Unit vector: ', VOUT
/// WRITE(*,'(A,F13.8)') 'Magnitude: ', VMAG
/// WRITE(*,*) ' '
///
/// END DO
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// Vector : 5.00000000 12.00000000 0.00000000
/// Unit vector: 0.38461538 0.92307692 0.00000000
/// Magnitude: 13.00000000
///
/// Vector : 0.00000010 0.00000020 0.00000020
/// Unit vector: 0.33333333 0.66666667 0.66666667
/// Magnitude: 0.00000030
/// ```
///
/// # Author and Institution
///
/// ```text
/// N.J. Bachman (JPL)
/// J. Diaz del Rio (ODC Space)
/// W.M. Owen (JPL)
/// W.L. Taber (JPL)
/// ```
///
/// # Version
///
/// ```text
/// - SPICELIB Version 1.1.0, 05-JUL-2021 (JDR)
///
/// Added IMPLICIT NONE statement.
///
/// Edited the header to comply with NAIF standard. Removed
/// unnecessary $Revisions section. Added complete example code.
///
/// - SPICELIB Version 1.0.2, 23-APR-2010 (NJB)
///
/// Header correction: assertions that the output
/// can overwrite the input have been removed.
///
/// - SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)
///
/// Comment section for permuted index source lines was added
/// following the header.
///
/// - SPICELIB Version 1.0.0, 31-JAN-1990 (WMO) (WLT)
/// ```
pub fn unorm(v1: &[f64; 3], vout: &mut [f64; 3], vmag: &mut f64) {
UNORM(v1, vout, vmag);
}
//$Procedure UNORM ( Unit vector and norm, 3 dimensional )
pub fn UNORM(V1: &[f64], VOUT: &mut [f64], VMAG: &mut f64) {
let V1 = DummyArray::new(V1, 1..=3);
let mut VOUT = DummyArrayMut::new(VOUT, 1..=3);
//
// SPICELIB functions
//
//
// Obtain the magnitude of V1
//
*VMAG = VNORM(V1.as_slice());
//
// If VMAG is nonzero, then normalize. Note that this process is
// numerically stable: overflow could only happen if VMAG were small,
// but this could only happen if each component of V1 were small.
// In fact, the magnitude of any vector is never less than the
// magnitude of any component.
//
if (*VMAG > 0.0) {
VOUT[1] = (V1[1] / *VMAG);
VOUT[2] = (V1[2] / *VMAG);
VOUT[3] = (V1[3] / *VMAG);
} else {
VOUT[1] = 0.0;
VOUT[2] = 0.0;
VOUT[3] = 0.0;
}
}