Procedure

   xpose_c ( Transpose a matrix, 3x3 ) 

   void xpose_c  ( ConstSpiceDouble  m1     [3][3],
                   SpiceDouble       mout   [3][3] )

Abstract

   Transpose a 3x3 matrix.

Required_Reading

   None.

Keywords

   MATRIX

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   m1         I   Matrix to be transposed.
   mout       O   Transpose of `m1'.

Detailed_Input

   m1          is any double precision 3x3 matrix.

Detailed_Output

   mout        is a double precision, 3x3 matrix which contains the
               transpose of `m1'. `mout' may overwrite `m1'.

Parameters

   None.

Exceptions

   Error free.

Files

   None.

Particulars

   xpose_c first copies the diagonal elements of `m1' to `mout'. Then
   the off-diagonal elements are transposed using a temporary
   variable in the following order:

      [0][1] <---> [1][0]
      [0][2] <---> [2][0]
      [1][2] <---> [2][1]

   Since a temporary variable is used, it is possible to transpose a
   matrix in place. In other words, `mout' may overwrite `m1'.

Examples

   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 a 3x3 double precision matrix, find its transpose.


      Example code begins here.


      /.
         Program xpose_ex1
      ./
      #include <stdio.h>
      #include "SpiceUsr.h"

      int main( )
      {

         /.
         Local variables.
         ./
         SpiceDouble          mout   [3][3];

         SpiceInt             i;

         /.
         Define the input matrix.
         ./
         SpiceDouble          m1     [3][3] = { { 1.0,  2.0,  3.0 },
                                                { 0.0,  4.0,  5.0 },
                                                { 0.0,  6.0,  0.0 }  };

         /.
         Compute the transpose of `m1'.
         ./
         xpose_c ( m1, mout );


         /.
         Display the results.
         ./
         printf( "Input matrix (M1):\n" );
         printf( "\n" );
         for ( i = 0; i < 3; i++ )
         {
            printf( "%5.1f %5.1f %5.1f\n", m1[i][0], m1[i][1], m1[i][2] );
         }
         printf( "\n" );
         printf( "Transpose of M1:\n" );
         printf( "\n" );
         for ( i = 0; i < 3; i++ )
         {
            printf( "%5.1f %5.1f %5.1f\n",
                         mout[i][0], mout[i][1], mout[i][2] );
         }

         return ( 0 );
      }


      When this program was executed on a Mac/Intel/cc/64-bit
      platform, the output was:


      Input matrix (M1):

        1.0   2.0   3.0
        0.0   4.0   5.0
        0.0   6.0   0.0

      Transpose of M1:

        1.0   0.0   0.0
        2.0   4.0   6.0
        3.0   5.0   0.0

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   W.M. Owen           (JPL)
   B.V. Semenov        (JPL)
   W.L. Taber          (JPL)
   E.D. Wright         (JPL)

Version

   -CSPICE Version 1.2.4, 10-AUG-2021 (BVS) (JDR)

       Edited the header to comply with NAIF standard. Added complete
       code example based on existing example.

   -CSPICE Version 1.2.3, 08-JAN-2014 (BVS)

       Corrected a minor typo in the header.

   -CSPICE Version 1.2.2, 16-JAN-2008 (EDW)

       Corrected typos in header titles:

       Detailed Input to -Detailed_Input
       Detailed Output to -Detailed_Output

   -CSPICE Version 1.2.1, 10-NOV-2006 (EDW)

       Added -Keywords and -Parameters section headers.
       Reordered section headers.

   -CSPICE Version 1.2.0, 22-OCT-1998 (NJB)

       Made input matrix const.

   -CSPICE Version 1.1.0, 06-MAR-1998 (EDW)

       Minor correction to header.

   -CSPICE Version 1.0.0, 08-FEB-1998 (NJB) (WLT) (WMO)

       Based on SPICELIB Version 1.0.1, 10-MAR-1992.

Index_Entries

   transpose a 3x3_matrix