Abstract

   CSPICE_CKOPN opens a new CK file, returning the handle
   of the opened file.

I/O

   Given:

      fname    the name of the CK file to open.

               [1,c1] = size(fname); char = class(fname)

                  or

               [1,1] = size(fname); cell = class(fname)

      ifname   a descriptive internal filename for the CK.

               [1,c2] = size(ifname); char = class(ifname)

                  or

               [1,1] = size(ifname); cell = class(ifname)

      ncomch   the number of characters to reserve for comments.

               [1,1] = size(ncomch); int32 = class(ncomch)

   the call:

      [handle] = cspice_ckopn( name, ifname, ncomch )

   returns:

      handle   the file handle assigned to `fname'

               [1,1] = size(handle); int32 = class(handle)

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) Create a CK type 3 segment; fill with data for a simple time
      dependent rotation and angular velocity, and reserve room in
      the CK comments area for 5000 characters.

      Example code begins here.


      function ckopn_ex1()

         INST3      = -77703;
         NCOMCH     = 5000;
         REF        = 'J2000';
         CK3        = 'ckopn_ex1.bc';
         IFNAME     = 'Test CK type 3 created by cspice_ckw03';
         SEGID3     = 'Test type 3 segment test CK';
         SECPERTICK = 0.001;
         SPACING    = 10.0;
         MAXREC     = 50;

         %
         % Note, sclkdp is a vector input, not a vectorized scalar.
         %
         sclkdp    = [1:MAXREC]';
         sclkdp    = (sclkdp - 1)*SPACING;

         spinrate  = [1:MAXREC]*1.e-6;

         theta     = [0:MAXREC-1]*SPACING;
         theta     = theta .* spinrate;

         %
         % Create a zero-filled array for the angular velocity
         % vectors. This allocates the needed memory and
         % defines a variable of the correct shape.
         %
         expavvs = zeros( [3 MAXREC] );

         a1 = zeros( [1 MAXREC] );
         a2 = a1;

         size(theta)
         size(a2)
         size(a1)
         r  = cspice_eul2m( theta, a2, a1, 3, 1 ,3 );
         q  = cspice_m2q( r );

         %
         % Fill the z component of the expavvs vectors with the
         % corresponding spinrate element scaled to SECPERTICK.
         %
         expavvs(3,:) = spinrate/SECPERTICK;

         begtim = sclkdp(1);
         endtim = sclkdp(MAXREC);
         avflag = 1;

         starts = [1:(MAXREC/2)]';
         starts = (starts-1)*2*SPACING;

         %
         % Open a new CK, write the data, catch any errors.
         %
         try
            handle = cspice_ckopn( CK3, IFNAME, NCOMCH )
            cspice_ckw03( handle,  ...
                          begtim,  ...
                          endtim,  ...
                          INST3,   ...
                          REF,     ...
                          avflag,  ...
                          SEGID3,  ...
                          sclkdp,  ...
                          q,       ...
                          expavvs, ...
                          starts )
         catch

            error( [ 'Failure: ' lasterr] )
         end

         cspice_ckcls(handle)


      When this program is executed, no output is presented on
      screen. After run completion, a new CK file exists in the
      output directory.

Particulars

   Open a new CK file, reserving room for comments if requested.

   A cspice_ckcls call should balance every cspice_ckopn
   call.

Exceptions

   1)  If the value of `ncomch' is negative, a value of zero (0) will
       be used for the number of comment characters to be set aside
       for comments.

   2)  If an error occurs while attempting to open a CK file the
       value of `handle' will not represent a valid file handle.

   3)  If any of the input arguments, `fname', `ifname' or `ncomch',
       is undefined, an error is signaled by the Matlab error
       handling system.

   4)  If any of the input arguments, `fname', `ifname' or `ncomch',
       is not of the expected type, or it does not have the expected
       dimensions and size, an error is signaled by the Mice
       interface.

Files

   See `fname' and `handle'.

Restrictions

   None.

Required_Reading

   MICE.REQ
   CK.REQ

Literature_References

   None.

Author_and_Institution

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

Version

   -Mice Version 1.1.0, 26-NOV-2021 (EDW) (JDR)

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

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

       Eliminated use of "lasterror" in rethrow.

       Removed reference to the function's corresponding CSPICE header from
       -Required_Reading section.

   -Mice Version 1.0.1, 29-OCT-2014 (EDW)

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

   -Mice Version 1.0.0, 22-NOV-2005 (EDW)

Index_Entries

   open a new CK file