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//
// GENERATED FILE
//
use super::*;
use crate::SpiceContext;
use f2rust_std::*;
/// Vector norm, general dimension
///
/// Compute the magnitude of a double precision vector of arbitrary
/// dimension.
///
/// # Brief I/O
///
/// ```text
/// VARIABLE I/O DESCRIPTION
/// -------- --- --------------------------------------------------
/// V1 I Vector whose magnitude is to be found.
/// NDIM I Dimension of V1.
///
/// The function returns the magnitude of V1.
/// ```
///
/// # Detailed Input
///
/// ```text
/// V1 is any double precision vector of arbitrary dimension.
///
/// NDIM is the dimension of the input vector V1.
/// ```
///
/// # Detailed Output
///
/// ```text
/// The function returns the magnitude of V1 calculated in a
/// numerically stable way.
/// ```
///
/// # Exceptions
///
/// ```text
/// Error free.
/// ```
///
/// # Particulars
///
/// ```text
/// VNORMG finds the component of V1 whose magnitude is the largest.
/// If the absolute magnitude of that component indicates that a
/// numeric overflow would occur when it is squared, or if it
/// indicates that an underflow would occur when squared (falsely
/// giving a magnitude of zero) then the following expression is
/// used:
///
/// VNORMG = V1MAX * MAGNITUDE OF [ (1/V1MAX)*V1 ]
///
/// Otherwise a simpler expression is used:
///
/// VNORMG = MAGNITUDE OF [ V1 ]
///
/// Beyond the logic described above, no further checking of the
/// validity of the input is performed.
/// ```
///
/// # 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) Define a four-dimensional vector and calculate its magnitude.
///
/// Example code begins here.
///
///
/// PROGRAM VNORMG_EX1
/// IMPLICIT NONE
///
/// C
/// C SPICELIB functions
/// C
/// DOUBLE PRECISION VNORMG
///
/// C
/// C Local parameters.
/// C
/// INTEGER NDIM
/// PARAMETER ( NDIM = 4 )
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION V1 ( NDIM )
///
/// DATA V1 / 12.3D0, -4.32D0,
/// . 76.0D0, 1.87D0 /
///
/// C
/// C Compute the magnitude of V1
/// C
/// WRITE(*,*) 'Magnitude of v1: ', VNORMG ( V1, NDIM )
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// Magnitude of v1: 77.132673362201047
///
///
/// 2) The following table show the correlation between various input
/// vectors V1 and VNORMG:
///
/// NDIM V1(NDIM) VNORMG
/// -------------------------------------------------
/// 1 (-7.0D20) 7.D20
/// 3 (1.D0, 2.D0, 2.D0) 3.D0
/// 4 (3.D0, 3.D0, 3.D0, 3.D0) 6.D0
/// 5 (5.D0, 12.D0, 0.D0, 0.D0, 0.D0) 13.D0
/// 3 (-5.D-17, 0.D0, 12.D-17) 13.D-17
/// ```
///
/// # Author and Institution
///
/// ```text
/// J. Diaz del Rio (ODC Space)
/// W.M. Owen (JPL)
/// W.L. Taber (JPL)
/// ```
///
/// # Version
///
/// ```text
/// - SPICELIB Version 1.1.0, 06-JUL-2021 (JDR)
///
/// Edited the header comments to comply with NAIF standard. Added
/// complete code example.
///
/// Added IMPLICIT NONE statement.
///
/// - 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 vnormg(v1: &[f64], ndim: i32) -> f64 {
let ret = VNORMG(v1, ndim);
ret
}
//$Procedure VNORMG ( Vector norm, general dimension )
pub fn VNORMG(V1: &[f64], NDIM: i32) -> f64 {
let V1 = DummyArray::new(V1, 1..=NDIM);
let mut VNORMG: f64 = 0.0;
let mut V1MAX: f64 = 0.0;
let mut A: f64 = 0.0;
//
// Local variables.
//
//
// Determine the maximum component of the vector.
//
V1MAX = 0.0;
for I in 1..=NDIM {
if (f64::abs(V1[I]) > V1MAX) {
V1MAX = f64::abs(V1[I]);
}
}
//
// If the vector is zero, return zero; otherwise normalize first.
// Normalizing helps in the cases where squaring would cause overflow
// or underflow. In the cases where such is not a problem it not worth
// it to optimize further.
//
if (V1MAX == 0.0) {
VNORMG = 0.0;
} else {
VNORMG = 0.0;
for I in 1..=NDIM {
A = (V1[I] / V1MAX);
VNORMG = (VNORMG + (A * A));
}
VNORMG = (V1MAX * f64::sqrt(VNORMG));
}
//
VNORMG
}