Abstract

   CSPICE_DSKGTL retrieves the value of a specified DSK tolerance
   or margin parameter.

I/O

   Given:

      keywrd   an integer code specifying the parameter to retrieve.

               help, keywrd
                  LONG = Scalar

               See the include file IcyDtl.pro for a description of the
               possible keywords.

   the call:

      cspice_dskgtl, keywrd, dpval

   returns:

      dpval    the value of the parameter specified by `keywrd'.

               help, dpval
                  DOUBLE = Scalar

Parameters

   See the include file

      IcyDtl.pro

   for descriptions and values of the tolerance or margin parameters
   accessed by this routine, and of the keyword parameters used to
   refer to them.

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) Retrieve the DSK tolerance keys and their corresponding values.
      Alter the values of those parameters for which it is possible,
      and confirm the change.

      Example code begins here.


      PRO dskgtl_ex1

         ;;
         ;; Retrieve the DSK tolerance keys and corresponding values.
         ;;
         @IcyUser

         ;;
         ;; Define an array of keys, and an array of key names.
         ;;
         dskkeys = [ SPICE_DSK_KEYXFR, SPICE_DSK_KEYSGR,  $
                     SPICE_DSK_KEYSPM, SPICE_DSK_KEYPTM,  $
                     SPICE_DSK_KEYAMG, SPICE_DSK_KEYLAL ]

         knames = [ 'SPICE_DSK_KEYXFR', 'SPICE_DSK_KEYSGR',  $
                    'SPICE_DSK_KEYSPM', 'SPICE_DSK_KEYPTM',  $
                    'SPICE_DSK_KEYAMG', 'SPICE_DSK_KEYLAL' ]


         ;;
         ;; Output the tolerance keys and values.
         ;;
         for i= 0, ( n_elements(dskkeys) -1 ) do begin

            cspice_dskgtl, dskkeys[i], dpval

            print, 'Key ', knames[i]
            print, '   key value ', dskkeys[i]
            print, '   parameter value ',dpval

         endfor

         print
         ;;
         ;; Alter the values of the parameters. Note, you cannot change
         ;; parameters SPICE_DSK_KEYAMG and SPICE_DSK_KEYLAL.
         ;; Confirm the change.
         ;;
         for i=0, 3 do begin

            cspice_dskstl, dskkeys[i], i*10
            cspice_dskgtl, dskkeys[i], dpval

            print, 'Key ', knames[i]
            print, '   key value ', dskkeys[i]
            print, '   new parameter value ',dpval

         endfor

      END


      When this program was executed on a Mac/Intel/IDL8.x/64-bit
      platform, the output was:


      Key SPICE_DSK_KEYXFR
         key value        1
         parameter value    1.0000000e-10
      Key SPICE_DSK_KEYSGR
         key value        2
         parameter value    1.0000000e-08
      Key SPICE_DSK_KEYSPM
         key value        3
         parameter value    1.0000000e-10
      Key SPICE_DSK_KEYPTM
         key value        4
         parameter value    1.0000000e-07
      Key SPICE_DSK_KEYAMG
         key value        5
         parameter value    1.0000000e-12
      Key SPICE_DSK_KEYLAL
         key value        6
         parameter value    1.0000000e-12

      Key SPICE_DSK_KEYXFR
         key value        1
         new parameter value        0.0000000
      Key SPICE_DSK_KEYSGR
         key value        2
         new parameter value        10.000000
      Key SPICE_DSK_KEYSPM
         key value        3
         new parameter value        20.000000
      Key SPICE_DSK_KEYPTM
         key value        4
         new parameter value        30.000000

Particulars

   The DSK tolerance routines centralize numeric tolerance and margin
   values used by the DSK subsystem. The DSK subsystem retrieves values
   from the DSK tolerance subsystem to use at run time.

   The DSK tolerance access functions are

      cspice_dskgtl {DSK, get tolerance value}
      cspice_dskstl {DSK, set tolerance value}

   To minimize run time overhead, the "keywords" used by these routines
   to identify parameters are actually integer codes.

   SPICE users may override certain values maintained by this subsystem;
   others values are fixed. It is recommended that any change to the
   tolerance values made at run time be performed only by expert SPICE
   users.

Exceptions

   1)  If the input keyword is not recognized, the error
       SPICE(INDEXOUTOFRANGE) is signaled by a routine in the call
       tree of this routine.

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

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

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

Files

   None.

Restrictions

   None.

Required_Reading

   ICY.REQ
   DSK.REQ

Literature_References

   None.

Author_and_Institution

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

Version

   -Icy Version 1.0.1, 31-MAY-2021 (JDR)

       Edited the header to comply with NAIF standard. Added example's problem
       statement.

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

       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 1.0.0, 13-DEC-2016 (ML) (EDW)

Index_Entries

   retrieve DSK tolerance or margin parameters