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//
// GENERATED FILE
//
use super::*;
use crate::SpiceContext;
use f2rust_std::*;
/// "V-Hat", unit vector along V, general dimension
///
/// Find the unit vector along a double precision vector of
/// arbitrary dimension.
///
/// # Brief I/O
///
/// ```text
/// VARIABLE I/O DESCRIPTION
/// -------- --- --------------------------------------------------
/// V1 I Vector to be normalized.
/// NDIM I Dimension of V1 (and also VOUT).
/// VOUT O Unit vector along V1.
/// ```
///
/// # Detailed Input
///
/// ```text
/// V1 is any double precision vector of arbitrary dimension.
///
/// NDIM is the dimension of V1 (and also VOUT).
/// ```
///
/// # Detailed Output
///
/// ```text
/// VOUT is the unit vector in the direction of V1:
///
/// V1
/// VOUT = --------
/// ||V1||
///
/// If V1 represents the zero vector, then VOUT will also be
/// the zero vector.
/// ```
///
/// # Exceptions
///
/// ```text
/// Error free.
/// ```
///
/// # Particulars
///
/// ```text
/// VHATG determines the magnitude of V1 and then divides each
/// component of V1 by the magnitude. This process is highly stable
/// over the whole range of multi-dimensional vectors.
///
/// This routine will detect if V1 the zero vector, and will not
/// attempt to divide by zero.
/// ```
///
/// # 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 n-dimensional vectors and find the unit vector
/// along each of them.
///
///
/// Example code begins here.
///
///
/// PROGRAM VHATG_EX1
/// IMPLICIT NONE
///
/// C
/// C Local parameters.
/// C
/// INTEGER NDIM
/// PARAMETER ( NDIM = 4 )
///
/// INTEGER SETSIZ
/// PARAMETER ( SETSIZ = 2 )
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION V1 ( NDIM, SETSIZ )
/// DOUBLE PRECISION VOUT ( NDIM )
///
/// INTEGER I
/// INTEGER J
///
/// C
/// C Define the vector set.
/// C
/// DATA V1 /
/// . 5.D0, 12.D0, 0.D0, 0.D0,
/// . 1.D-7, 2.D-7, 2.D-7, 0.D0 /
///
/// C
/// C Calculate the unit vectors.
/// C
/// DO I=1, SETSIZ
///
/// CALL VHATG ( V1(1,I), NDIM, VOUT )
///
/// WRITE(*,'(A,4F12.7)') 'Input vector: ',
/// . ( V1(J,I), J=1,NDIM )
/// WRITE(*,'(A,4F12.7)') 'Unit vector : ', VOUT
/// WRITE(*,*)
///
/// END DO
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// Input vector: 5.0000000 12.0000000 0.0000000 0.0000000
/// Unit vector : 0.3846154 0.9230769 0.0000000 0.0000000
///
/// Input vector: 0.0000001 0.0000002 0.0000002 0.0000000
/// Unit vector : 0.3333333 0.6666667 0.6666667 0.0000000
/// ```
///
/// # Restrictions
///
/// ```text
/// 1) The relative number of cases whereby floating point overflow
/// may occur is negligible. Thus, no error recovery or reporting
/// scheme is incorporated into this subroutine.
/// ```
///
/// # 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. Added complete
/// code example based on existing example.
///
/// - SPICELIB Version 1.0.2, 22-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)
/// ```
pub fn vhatg(v1: &[f64], ndim: i32, vout: &mut [f64]) {
VHATG(v1, ndim, vout);
}
//$Procedure VHATG ( "V-Hat", unit vector along V, general dimension )
pub fn VHATG(V1: &[f64], NDIM: i32, VOUT: &mut [f64]) {
let V1 = DummyArray::new(V1, 1..=NDIM);
let mut VOUT = DummyArrayMut::new(VOUT, 1..=NDIM);
let mut VMAG: f64 = 0.0;
//
// SPICELIB functions
//
//
// Local variables
//
//
// Obtain the magnitude of V1
//
VMAG = VNORMG(V1.as_slice(), NDIM);
//
// 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) {
for I in 1..=NDIM {
VOUT[I] = (V1[I] / VMAG);
}
} else {
for I in 1..=NDIM {
VOUT[I] = 0.0;
}
}
//
}