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//
// GENERATED FILE
//
use super::*;
use crate::SpiceContext;
use f2rust_std::*;
/// Vector norm, 3 dimensions
///
/// Compute the magnitude of a double precision 3-dimensional
/// vector.
///
/// # Brief I/O
///
/// ```text
/// VARIABLE I/O DESCRIPTION
/// -------- --- --------------------------------------------------
/// V1 I Vector whose magnitude is to be found.
///
/// The function returns the magnitude of V1.
/// ```
///
/// # Detailed Input
///
/// ```text
/// V1 is any double precision 3-dimensional vector.
/// ```
///
/// # Detailed Output
///
/// ```text
/// The function returns the magnitude of V1 calculated in a
/// numerically stable way.
/// ```
///
/// # Exceptions
///
/// ```text
/// Error free.
/// ```
///
/// # Particulars
///
/// ```text
/// VNORM takes care to avoid overflow while computing the norm of the
/// input vector V1. VNORM finds the component of V1 whose magnitude
/// is the largest. Calling this magnitude V1MAX, the norm is computed
/// using the formula:
///
/// || 1 ||
/// VNORM = V1MAX * || ------- * V1 ||
/// || V1MAX ||
///
/// where the notation ||X|| indicates the norm of the vector X.
/// ```
///
/// # 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 3-dimensional vectors and compute the
/// magnitude of each vector within.
///
///
/// Example code begins here.
///
///
/// PROGRAM VNORM_EX1
/// IMPLICIT NONE
///
/// C
/// C SPICELIB functions.
/// C
/// DOUBLE PRECISION VNORM
///
/// C
/// C Local parameters.
/// C
/// INTEGER SETSIZ
/// PARAMETER ( SETSIZ = 3 )
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION V1 ( 3, SETSIZ )
///
/// INTEGER I
/// INTEGER J
///
/// C
/// C Define a set of 3-dimensional vectors.
/// C
/// DATA V1 / 1.D0, 2.D0, 2.D0,
/// . 5.D0, 12.D0, 0.D0,
/// . -5.D-17, 0.0D0, 12.D-17 /
///
/// C
/// C Calculate the magnitude of each vector
/// C
/// DO I=1, SETSIZ
///
/// WRITE(*,'(A,3E10.2)') 'Input vector: ',
/// . ( V1(J,I), J=1,3 )
/// WRITE(*,'(A,F24.20)') 'Magnitude : ',
/// . VNORM ( V1(1,I) )
/// WRITE(*,*)
///
/// END DO
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// Input vector: 0.10E+01 0.20E+01 0.20E+01
/// Magnitude : 3.00000000000000000000
///
/// Input vector: 0.50E+01 0.12E+02 0.00E+00
/// Magnitude : 13.00000000000000000000
///
/// Input vector: -0.50E-16 0.00E+00 0.12E-15
/// Magnitude : 0.00000000000000013000
/// ```
///
/// # Author and Institution
///
/// ```text
/// J. Diaz del Rio (ODC Space)
/// W.M. Owen (JPL)
/// W.L. Taber (JPL)
/// ```
///
/// # Version
///
/// ```text
/// - SPICELIB Version 1.0.2, 06-JUL-2020 (JDR)
///
/// Added IMPLICIT NONE statement.
///
/// Edited the header to comply with NAIF standard. Added complete
/// code example.
///
/// - 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 vnorm(v1: &[f64; 3]) -> f64 {
let ret = VNORM(v1);
ret
}
//$Procedure VNORM ( Vector norm, 3 dimensions )
pub fn VNORM(V1: &[f64]) -> f64 {
let V1 = DummyArray::new(V1, 1..=3);
let mut VNORM: f64 = 0.0;
let mut V1MAX: f64 = 0.0;
//
// Determine the maximum component of the vector.
//
V1MAX = intrinsics::DMAX1(&[f64::abs(V1[1]), f64::abs(V1[2]), f64::abs(V1[3])]);
//
// 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) {
VNORM = 0.0;
} else {
VNORM = (V1MAX
* f64::sqrt(
((f64::powi((V1[1] / V1MAX), 2) + f64::powi((V1[2] / V1MAX), 2))
+ f64::powi((V1[3] / V1MAX), 2)),
));
}
//
VNORM
}