Procedure

     WRENCD ( Write encoded d.p. numbers to text file )

     SUBROUTINE WRENCD ( UNIT, N, DATA )

Abstract

     Encode and write d.p. numbers to a text file.

Required_Reading

     None.

Keywords

     CONVERSION
     NUMBERS
     UTILITY

Declarations

     IMPLICIT NONE

     INTEGER               UNIT
     INTEGER               N
     DOUBLE PRECISION      DATA(*)

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     UNIT      I    Fortran unit number of output text file.
     N         I    Number of d.p. numbers to encode and write.
     DATA      I    List of d.p. numbers to encode and write.

Detailed_Input

     UNIT     is the Fortran unit number for a previously opened text
              file. All writing will begin at the CURRENT POSITION
              in the text file.

     N        is the number of double precision numbers to be encoded
              and written to the text file attached to UNIT.

     DATA     is the list of double precision numbers to be encoded and
              written to the text file attached to UNIT.

Detailed_Output

     See the $Particulars section for a description of the effect of
     this routine.

Parameters

     None.

Exceptions

     1)  If N, the number of data items, is not positive, the error
         SPICE(INVALIDARGUMENT) is signaled.

     2)  If an error occurs while writing to the text file attached
         to UNIT, the error SPICE(FILEWRITEFAILED) is signaled.

     3)  If the Fortran logical unit UNIT is not defined, the results
         of this routine are unpredictable.

Files

     See the description of UNIT in the $Detailed_Input section.

Particulars

     This routine will accept a list of one or more double precision
     numbers which it will encode into equivalent text strings and
     write to the current position in a text file. The current
     position in a file is defined to be the text line immediately
     following the last text line that was written or read. The
     encoded d.p. numbers are written to the output text file as
     quoted character strings so that a Fortran list directed read may
     be used to read the encoded values, rather than a formatted read
     with the format specifier FMT = '(A)'.

     This routine is one of a pair of routines which are used to
     encode and decode d.p. numbers:

           WRENCD -- Encode and write d.p. numbers to a file.
           RDENCD -- Read and decode d.p. numbers from a file.

     The encoding/decoding of d.p.numbers is performed to provide a
     portable means for transferring data values.

     Currently the text string produced will be in a base 16
     ``scientific notation.'' This format retains the full precision
     available for d.p. numbers on any given computer architecture.
     See DP2HX.FOR and HX2DP.FOR for details.

Examples

     Please note that the output format in the examples is not
     intended to be exactly identical with the output format of this
     routine in actual use. The output format used in the examples is
     intended to aid in the understanding of how this routine works.
     It is NOT intended to be a specification of the output format for
     this routine.

     Let

        UNIT     be the Fortran logical unit of a previously opened
                 text file.

        N        = 100

        DATA(I)  = DBLE(I), I = 1,N

     Then, the subroutine call

           CALL WRENCD( UNIT, N, DATA )

     will write the first 100 integers as encoded d.p. numbers to the
     output text file attached to UNIT, beginning at the current
     position in the output file, which is marked by an arrow, '-->'.
     The resulting output will look something like the following:

        -->'1^1' '2^1' '3^1' '4^1' '5^1' '6^1' '7^1' '8^1' '9^1'
           'A^1' 'B^1' 'C^1' 'D^1' 'E^1' 'F^1' '1^2' '11^2' '12^2'
           '13^2' '14^2' '15^2' '16^2' '17^2' '18^2' '19^2' '1A^2'
           '1B^2' '1C^2' '1D^2' '1E^2' '1F^2' '2^2' '21^2' '22^2'
           '23^2' '24^2' '25^2' '26^2' '27^2' '28^2' '29^2' '2A^2'
           '2B^2' '2C^2' '2D^2' '2E^2' '2F^2' '3^2' '31^2' '32^2'
           '33^2' '34^2' '35^2' '36^2' '37^2' '38^2' '39^2' '3A^2'
           '3B^2' '3C^2' '3D^2' '3E^2' '3F^2' '4^2'
           '41^2' '42^2' '43^2' '44^2' '45^2' '46^2' '47^2' '48^2'
           '49^2' '4A^2' '4B^2' '4C^2' '4D^2' '4E^2' '4F^2' '5^2'
           '51^2' '52^2' '53^2' '54^2' '55^2' '56^2' '57^2' '58^2'
           '59^2' '5A^2' '5B^2' '5C^2' '5D^2' '5E^2' '5F^2' '6^2'
           '61^2' '62^2' '63^2' '64^2'
        -->

     At this point, the arrow marks the position of the file pointer
     immediately after the call to WRENCD.

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     K.R. Gehringer     (JPL)

Version

    SPICELIB Version 1.3.0, 13-AUG-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.2.0, 09-SEP-1993 (KRG)

        The list directed write was changed to a formatted write using
        the specifier FMT='(A)'. This was done in order to prevent a
        space from appearing as the first character on each line of the
        file for certain computer platforms.

    SPICELIB Version 1.1.0, 21-JUN-1993 (KRG)

        This routine was modified to avoid the creation of long output
        lines on some of the supported systems, such as the NeXT with
        Absoft Fortran 3.2.

        A disclaimer was added to the $Examples section concerning
        the output format used. The disclaimer simply states that the
        output format used in the example is not necessarily the
        output format actually used by the routine.

    SPICELIB Version 1.0.0, 20-OCT-1992 (KRG)