pub fn rdencd(
ctx: &mut SpiceContext<'_>,
unit: i32,
n: i32,
data: &mut [f64],
) -> Result<()>Expand description
Read encoded d.p. numbers from file
Read N encoded d.p. numbers from a text file, decoding them into their equivalent d.p. numbers.
§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.§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.§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)