Abstract

   CSPICE_VADD adds two double precision 3-dimensional vectors.

I/O

   Given:

      v1,
      v2       two arbitrary double precision 3-dimensional vectors.

               help, v1
                  DOUBLE = Array[3]
               help, v2
                  DOUBLE = Array[3]

   the call:

      cspice_vadd, v1, v2, vout

   returns:

      vout     the double precision 3-dimensional vector sum of `v1' and `v2'.

               help, vout
                  DOUBLE = Array[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) Define two sets of 3-dimensional vectors and compute the sum
      of each vector in first set with the corresponding vector in
      the second set.


      Example code begins here.


      PRO vadd_ex1

         ;;
         ;; Local parameters.
         ;;
         SETSIZ =   2L

         ;;
         ;; Define the two vector sets.
         ;;
         seta   = [ [ 1.D0,  2.D0,  3.D0 ], [ 1.D-7, 1.D23, 1.D-9 ] ]

         setb   = [ [ 4.D0,  5.D0,  6.D0 ], [ 1.D24, 1.D23, 0.D0  ] ]

         ;;
         ;; Calculate the sum of each pair of vectors
         ;;
         for i=0L, SETSIZ-1L do begin

            cspice_vadd, seta[*,i], setb[*,i], vout

            print, format='(A,3E11.2)', 'Vector A  : ', seta[*,i]
            print, format='(A,3E11.2)', 'Vector B  : ', setb[*,i]
            print, format='(A,3E11.2)', 'Sum vector: ', vout
            print, ' '

         endfor

      END


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


      Vector A  :    1.00E+00   2.00E+00   3.00E+00
      Vector B  :    4.00E+00   5.00E+00   6.00E+00
      Sum vector:    5.00E+00   7.00E+00   9.00E+00

      Vector A  :    1.00E-07   1.00E+23   1.00E-09
      Vector B  :    1.00E+24   1.00E+23   0.00E+00
      Sum vector:    1.00E+24   2.00E+23   1.00E-09

Particulars

   This routine simply performs addition between components of `v1'
   and `v2'. No checking is performed to determine whether floating
   point overflow has occurred.

   Native IDL code to calculate the same vector result:

      sum = vec1 + vec2

   The IDL '+' operator accepts arbitrary size N vectors.

Exceptions

   1)  If any of the input arguments, `v1' or `v2', is undefined, an
       error is signaled by the IDL error handling system.

   2)  If any of the input arguments, `v1' or `v2', 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 `vout' is not a named variable, an
       error is signaled by the Icy interface.

Files

   None.

Restrictions

   1)  The user is required to determine that the magnitude each
       component of the vectors is within the appropriate range so as
       not to cause floating point overflow.

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

   3-dimensional vector addition