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//
// GENERATED FILE
//
use super::*;
use crate::SpiceContext;
use f2rust_std::*;
/// Matrix times matrix transpose, 3x3
///
/// Multiply a 3x3 matrix and the transpose of another 3x3 matrix.
///
/// # Brief I/O
///
/// ```text
/// VARIABLE I/O DESCRIPTION
/// -------- --- --------------------------------------------------
/// M1 I 3x3 double precision matrix.
/// M2 I 3x3 double precision matrix.
/// MOUT O The product M1 times transpose of M2.
/// ```
///
/// # Detailed Input
///
/// ```text
/// M1 is an arbitrary 3x3 double precision matrix.
///
/// M2 is an arbitrary 3x3 double precision matrix.
/// Typically, M2 will be a rotation matrix since
/// then its transpose is its inverse (but this is
/// NOT a requirement).
/// ```
///
/// # Detailed Output
///
/// ```text
/// MOUT is a 3x3 double precision matrix. MOUT is the product
///
/// T
/// MOUT = M1 x M2
/// ```
///
/// # Exceptions
///
/// ```text
/// Error free.
/// ```
///
/// # Particulars
///
/// ```text
/// The code reflects precisely the following mathematical expression
///
/// For each value of the subscripts I and J from 1 to 3:
///
/// 3
/// .-----
/// \
/// MOUT(I,J) = ) M1(I,K) * M2(J,K)
/// /
/// '-----
/// K=1
///
/// Note that the reversal of the K and J subscripts in the right-
/// hand matrix M2 is what makes MOUT the product of the TRANSPOSE of
/// M2 and not simply of M2 itself.
/// ```
///
/// # 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) Given two 3x3 double precision matrices, multiply the first
/// matrix by the transpose of the second one.
///
///
/// Example code begins here.
///
///
/// PROGRAM MXMT_EX1
/// IMPLICIT NONE
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION M1 ( 3, 3 )
/// DOUBLE PRECISION M2 ( 3, 3 )
/// DOUBLE PRECISION MOUT ( 3, 3 )
///
/// INTEGER I
/// INTEGER J
///
/// C
/// C Define M1.
/// C
/// DATA M1 / 0.0D0, -1.0D0, 0.0D0,
/// . 1.0D0, 0.0D0, 0.0D0,
/// . 0.0D0, 0.0D0, 1.0D0 /
///
/// C
/// C Make M2 equal to M1.
/// C
/// CALL MEQU ( M1, M2 )
///
/// C
/// C Multiply M1 by the transpose of M2.
/// C
/// CALL MXMT ( M1, M2, MOUT )
///
/// WRITE(*,'(A)') 'M1:'
/// DO I=1, 3
///
/// WRITE(*,'(3F16.7)') ( M1(I,J), J=1,3 )
///
/// END DO
///
/// WRITE(*,*)
/// WRITE(*,'(A)') 'M2:'
/// DO I=1, 3
///
/// WRITE(*,'(3F16.7)') ( M2(I,J), J=1,3 )
///
/// END DO
///
/// WRITE(*,*)
/// WRITE(*,'(A)') 'M1 times transpose of M2:'
/// DO I=1, 3
///
/// WRITE(*,'(3F16.7)') ( MOUT(I,J), J=1,3 )
///
/// END DO
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// M1:
/// 0.0000000 1.0000000 0.0000000
/// -1.0000000 0.0000000 0.0000000
/// 0.0000000 0.0000000 1.0000000
///
/// M2:
/// 0.0000000 1.0000000 0.0000000
/// -1.0000000 0.0000000 0.0000000
/// 0.0000000 0.0000000 1.0000000
///
/// M1 times transpose of M2:
/// 1.0000000 0.0000000 0.0000000
/// 0.0000000 1.0000000 0.0000000
/// 0.0000000 0.0000000 1.0000000
/// ```
///
/// # Restrictions
///
/// ```text
/// 1) The user is responsible for checking the magnitudes of the
/// elements of M1 and M2 so that a floating point overflow does
/// not occur. (In the typical use where M1 and M2 are rotation
/// matrices, this not a risk at all.)
/// ```
///
/// # 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, 06-JUL-2021 (JDR)
///
/// Added IMPLICIT NONE statement.
///
/// Edited the header to comply with NAIF standard. Added complete
/// code examples based on existing code fragments.
///
/// - 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 mxmt(m1: &[[f64; 3]; 3], m2: &[[f64; 3]; 3], mout: &mut [[f64; 3]; 3]) {
MXMT(
m1.as_flattened(),
m2.as_flattened(),
mout.as_flattened_mut(),
);
}
//$Procedure MXMT ( Matrix times matrix transpose, 3x3 )
pub fn MXMT(M1: &[f64], M2: &[f64], MOUT: &mut [f64]) {
let M1 = DummyArray2D::new(M1, 1..=3, 1..=3);
let M2 = DummyArray2D::new(M2, 1..=3, 1..=3);
let mut MOUT = DummyArrayMut2D::new(MOUT, 1..=3, 1..=3);
let mut PRODM = StackArray2D::<f64, 9>::new(1..=3, 1..=3);
//
// Local variables
//
//
// Perform the matrix multiplication
//
for I in 1..=3 {
for J in 1..=3 {
PRODM[[I, J]] = (((M1[[I, 1]] * M2[[J, 1]]) + (M1[[I, 2]] * M2[[J, 2]]))
+ (M1[[I, 3]] * M2[[J, 3]]));
}
}
//
// Move the result into MOUT
//
MOVED(PRODM.as_slice(), 9, MOUT.as_slice_mut());
}