Procedure

   dasudd_c ( DAS, update data, double precision ) 

   void dasudd_c ( SpiceInt            handle,
                   SpiceInt            first,
                   SpiceInt            last,
                   ConstSpiceDouble    data   [] )

Abstract

   Update data in a specified range of double precision addresses
   in a DAS file.

Required_Reading

   DAS

Keywords

   ARRAY
   ASSIGNMENT
   DAS
   FILES

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   handle     I   DAS file handle.
   first,
   last       I   Range of d.p. addresses to write to.
   data       I   An array of d.p. numbers.

Detailed_Input

   handle      is a file handle of a DAS file opened for writing.

   first,
   last        are the first and last of a range of DAS logical
               addresses of double precision numbers to update. These
               addresses satisfy the inequality

                  1  <=   first   <=   last   <=   lastd

               where `lastd' is the last double precision logical
               address in use in the DAS file designated by
               `handle'.

   data        is an array of double precision numbers. The
               array elements data[0] through data[n-1] will be
               written to the indicated DAS file, where `n' is
               last - first + 1.

Detailed_Output

   None.

   See -Particulars for a description of the effect of this routine.

Parameters

   None.

Exceptions

   1)  If the input file handle is invalid, an error is
       signaled by a routine in the call tree of this routine.

   2)  Only logical addresses that already contain data may be
       updated: if either `first' or `last' are outside the range

          [ 1,  lastd ]

       where `lastd' is the last double precision logical address that
       currently contains data in the indicated DAS file, the error
       SPICE(INVALIDADDRESS) is signaled by a routine in the call tree of
       this routine. The DAS file will not be modified.

   3)  If first > last but both addresses are valid, this routine
       will not modify the indicated DAS file. No error will be
       signaled.

   4)  If an I/O error occurs during the data update attempted
       by this routine, the error is signaled by a routine in the
       call tree of this routine.

Files

   See the description of the argument `handle' in -Detailed_Input.

Particulars

   This routine replaces the double precision data in the specified
   range of logical addresses within a DAS file with the contents of
   the input array `data'.

   The actual physical write operations that update the indicated
   DAS file with the contents of the input array `data' might not take
   place before this routine returns, since the DAS system buffers
   data that is written as well as data that is read. In any case,
   the data will be flushed to the file at the time the file is
   closed, if not earlier. A physical write of all buffered
   records can be forced by calling the CSPICE routine daswbr_c
   (DAS, write buffered records).

   In order to append double precision data to a DAS file, filling
   in a range of double precision logical addresses that starts
   immediately after the last double precision logical address
   currently in use, the CSPICE routine dasadd_c (DAS add data,
   double precision) should be used.

Examples

   The numerical results shown for this example may differ across
   platforms. The results depend on the SPICE kernels used as
   input, the compiler and supporting libraries, and the machine
   specific arithmetic implementation.

   1) Write to addresses 1 through 200 in a DAS file in random-access
      fashion by updating the file. Recall that data must be present
      in the file before it can be updated.


      Example code begins here.


      /.
         Program dasudd_ex1
      ./
      #include <stdio.h>
      #include "SpiceUsr.h"

      int main( )
      {

         /.
         Local parameters.
         ./
         #define FNAME        "dasudd_ex1.das"
         #define TYPE         "TEST"

         /.
         Local variables.
         ./
         SpiceDouble          data   [200];
         SpiceDouble          udata;

         SpiceInt             handle;
         SpiceInt             i;
         SpiceInt             j;

         /.
         Open a new DAS file. Use the file name as the internal
         file name, and reserve no records for comments.
         ./
         dasonw_c ( FNAME, TYPE, FNAME, 0, &handle );

         /.
         Append 200 double precision numbers to the file;
         after the data are present, we're free to update it
         in any order we please.  (cleard_c zeros out a double
         precision array.)
         ./
         cleard_c ( 200, data );
         dasadd_c ( handle, 200, data );

         /.
         Now the double precision logical addresses 1:200
         can be written to in random-access fashion.  We'll
         fill them in reverse order.
         ./
         for ( i = 200; i >= 1; i -= 1 )
         {
            udata = (double)i;
            dasudd_c ( handle, i, i, &udata );
         }

         /.
         Close the file.
         ./
         dascls_c ( handle );

         /.
         Now make sure that we updated the file properly.
         Open the file for reading and dump the contents
         of the double precision logical addresses 1:200.
         ./
         dasopr_c ( FNAME, &handle );

         cleard_c ( 200, data );
         dasrdd_c ( handle, 1, 200, data );

         printf( "\n" );
         printf( "Data from \"%s\":\n", FNAME );
         printf( "\n" );
         for ( i = 0; i < 25; i++ )
         {
            for ( j = 0; j < 8; j++ )
            {
               printf( "%7.1f", data[i*8+j] );
            }
            printf( "\n" );
         }

         /.
         Close the file.
         ./
         dascls_c ( handle );

         return ( 0 );
      }


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


      Data from "dasudd_ex1.das":

          1.0    2.0    3.0    4.0    5.0    6.0    7.0    8.0
          9.0   10.0   11.0   12.0   13.0   14.0   15.0   16.0
         17.0   18.0   19.0   20.0   21.0   22.0   23.0   24.0
         25.0   26.0   27.0   28.0   29.0   30.0   31.0   32.0
         33.0   34.0   35.0   36.0   37.0   38.0   39.0   40.0
         41.0   42.0   43.0   44.0   45.0   46.0   47.0   48.0
         49.0   50.0   51.0   52.0   53.0   54.0   55.0   56.0
         57.0   58.0   59.0   60.0   61.0   62.0   63.0   64.0
         65.0   66.0   67.0   68.0   69.0   70.0   71.0   72.0
         73.0   74.0   75.0   76.0   77.0   78.0   79.0   80.0
         81.0   82.0   83.0   84.0   85.0   86.0   87.0   88.0
         89.0   90.0   91.0   92.0   93.0   94.0   95.0   96.0
         97.0   98.0   99.0  100.0  101.0  102.0  103.0  104.0
        105.0  106.0  107.0  108.0  109.0  110.0  111.0  112.0
        113.0  114.0  115.0  116.0  117.0  118.0  119.0  120.0
        121.0  122.0  123.0  124.0  125.0  126.0  127.0  128.0
        129.0  130.0  131.0  132.0  133.0  134.0  135.0  136.0
        137.0  138.0  139.0  140.0  141.0  142.0  143.0  144.0
        145.0  146.0  147.0  148.0  149.0  150.0  151.0  152.0
        153.0  154.0  155.0  156.0  157.0  158.0  159.0  160.0
        161.0  162.0  163.0  164.0  165.0  166.0  167.0  168.0
        169.0  170.0  171.0  172.0  173.0  174.0  175.0  176.0
        177.0  178.0  179.0  180.0  181.0  182.0  183.0  184.0
        185.0  186.0  187.0  188.0  189.0  190.0  191.0  192.0
        193.0  194.0  195.0  196.0  197.0  198.0  199.0  200.0


      Note that after run completion, a new DAS file exists in the
      output directory.

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   J. Diaz del Rio     (ODC Space)

Version

   -CSPICE Version 1.0.0, 16-JUL-2021 (JDR)

Index_Entries

   update double precision data in a DAS file