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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_AXISAR returns a 3x3 double rotation matrix that rotates
   vectors by a specified angle about a specified axis.

I/O


   Given:

      axis    the vector defining a rotation axis.

              [3,1] = size(axis); double = class(axis)

      angle   the angle in radians defining the measure of rotation
              about 'axis'.

              [1,1] = size(angle); double = class(angle)

   the call:

      r = cspice_axisar( axis, angle)

   returns:

      r   the operator for the coordinate transformation determined by
          'axis' and 'angle', i.e. the application of 'r' to a 3x1
          array returns the result of rotating the vector about 'axis'
          through 'angle' radians

           [3,3] = size(r); double = class(r)

   Please note cspice_raxisa is not guaranteed to invert the
   operation of cspice_axisar.

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.

      Example:

      %
      % Define an axis and an angle for rotation.
      %
      axis = [ 1.; 2.; 3. ];
      angle = .1 * cspice_twopi;

      %
      % Determine the rotation matrix.
      %
      rot_mat = cspice_axisar( axis, angle );

      %
      % Now calculate the rotation axis and angle based on the
      % matrix as input.
      %
      [ axout, angout ] = cspice_raxisa( rot_mat);

      %
      % Now input the axout and angout to cspice_axisar to
      % compare against the original rotation matrix rot_mat.
      %
      rot_out = cspice_axisar( axout, angout );
      rot_mat - rot_out

   MATLAB outputs:

         1.0e-15 *

                        0  -0.11102230246252   0.05551115123126
         0.11102230246252                  0                  0
        -0.05551115123126   0.02775557561563                  0

     The zero matrix accurate to round-off error. A numerical
     demonstration of equality.

Particulars


   None.

Required Reading


   For important details concerning this module's function, please refer to
   the CSPICE routine axisar_c.

   MICE.REQ
   ROTATION.REQ

Version


   -Mice Version 1.0.1, 28-OCT-2014, EDW (JPL)

      Edited I/O section to conform to NAIF standard for Mice documentation.

   -Mice Version 1.0.0, 29-NOV-2005, EDW (JPL)

Index_Entries


   axis and angle to rotation


Wed Apr  5 18:00:29 2017