Procedure

     RDENCD  ( Read encoded d.p. numbers from file )

     SUBROUTINE RDENCD ( UNIT, N, DATA )

Abstract

     Read N encoded d.p. numbers from a text file, decoding them
     into their equivalent d.p. numbers.

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 input text file.
     N         I    Number of d.p. numbers to read and decode.
     DATA      O    List of decoded d.p. numbers.

Detailed_Input

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

     N        is the number of encoded double precision numbers, to be
              read from the text file attached to UNIT.

Detailed_Output

     DATA     is the list of decoded double precision numbers read from
              the text file attached to UNIT.

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 reading from the text file attached
         to UNIT, the error SPICE(FILEREADFAILED) is signaled.

     3)  If an error occurs while decoding a number, the error
         SPICE(DECODINGERROR) is signaled.

Files

     See the description of UNIT in $Detailed_Input.

Particulars

     This routine will read N encoded double precision numbers from
     the current position in a previously opened 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 numbers will be decoded and placed into a list of
     double precision numbers which will be passed back to the caller.
     The encoded double precision numbers are represented 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 encoded d.p. numbers are represented in a base
     16 ``scientific notation.'' See DP2HX.FOR and HX2DP.FOR for
     details.

Examples

     Suppose we have the following input file which contains the
     values 1.0D0 - 100.0D0 in encoded format, and that the input
     file has already been opened for reading. The arrow, '-->',
     indicates the current position in the file.

        -->'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'

     Then the following code fragment would read and decode these
     100 values.

           N = 100
           CALL RDENCD( UNIT, N, DATA )

      Upon returning, the array data would contain the values
      1.0D0 - 100.0D0.

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

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

Version

    SPICELIB Version 1.2.0, 03-JUN-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard. Fixed I/O type
        of argument DATA in $Brief_I/O table.

    SPICELIB Version 1.1.0, 19-MAR-1999 (FST)

        Modified the long error message for SPICE(FILEREADFAILED)
        to indicate the possibility of an incomplete text transfer
        file as the cause.

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