Abstract

   CSPICE_XPOSE transposes a 3x3 matrix.

I/O

   Given:

      m1       any double precision 3x3 matrix.

               help, m1
                  DOUBLE = Array[3,3]

   the call:

      cspice_xpose, m1, mout

   returns:

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

               help, mout
                  DOUBLE = Array[3,3]

Parameters

   None.

Examples

   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

   1) Given a 3x3 double precision matrix, find its transpose.


      Example code begins here.


      PRO xpose_ex1

         ;;
         ;; Define the input matrix.
         ;;
         m1 = [ [ 1.D0,  2.D0,  3.D0 ],                                      $
                [ 0.D0,  4.D0,  5.D0 ],                                      $
                [ 0.D0,  6.D0,  0.D0 ]]

         ;;
         ;; Compute the transpose of `m1'.
         ;;
         cspice_xpose, m1, mout

         ;;
         ;; Display the results.
         ;;
         print, 'Input matrix (M1):'
         print
         print, format='(3F6.1)', m1
         print
         print, 'Transpose of M1:'
         print
         print, format='(3F6.1)', mout

      END


      When this program was executed on a Mac/Intel/IDL8.x/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

Particulars

   cspice_xpose 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]

   Native IDL code to calculate the same matrix result:

      mout = transpose(m1)

   The IDL transpose function accepts arbitrary NxM matrices.

Exceptions

   1)  If the input argument `m1' is undefined, an error is signaled
       by the IDL error handling system.

   2)  If the input argument `m1' is not of the expected type, or it
       does not have the expected dimensions and size, an error is
       signaled by the Icy interface.

   3)  If the output argument `mout' is not a named variable, an
       error is signaled by the Icy interface.

Files

   None.

Restrictions

   None.

Required_Reading

   ICY.REQ

Literature_References

   None.

Author_and_Institution

   J. Diaz del Rio     (ODC Space)
   E.D. Wright         (JPL)

Version

   -Icy Version 1.0.3, 10-AUG-2021 (JDR)

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

       Added -Parameters, -Exceptions, -Files, -Restrictions,
       -Literature_References and -Author_and_Institution sections, and
       completed -Particulars section.

       Removed reference to the routine's corresponding CSPICE header from
       -Abstract section.

       Added arguments' type and size information in the -I/O section.

   -Icy Version 1.0.2, 13-JUN-2011 (EDW)

      Edits to comply with NAIF standard for Icy headers.

   -Icy Version 1.0.1, 09-DEC-2005 (EDW)

      Added -Examples section.

   -Icy Version 1.0.0, 16-JUN-2003 (EDW)

Index_Entries

   transpose a 3x3 matrix