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Table of contents
Procedure
DAFUS ( DAF, unpack summary )
ENTRY DAFUS ( SUM, ND, NI, DC, IC )
Abstract
Unpack an array summary into its double precision and integer
components.
Required_Reading
DAF
Keywords
CONVERSION
FILES
Declarations
DOUBLE PRECISION SUM ( * )
INTEGER ND
INTEGER NI
DOUBLE PRECISION DC ( * )
INTEGER IC ( * )
Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
SUM I Array summary.
ND I Number of double precision components.
NI I Number of integer components.
DC O Double precision components.
IC O Integer components.
Detailed_Input
SUM is an array summary. This identifies the contents and
location of a single array within a DAF.
ND is the number of double precision components in
the summary.
NI is the number of integer components in the summary.
Detailed_Output
DC are the double precision components of the summary.
IC are the integer components of the summary.
Parameters
None.
Exceptions
Error free.
1) If ND is zero or negative, no double precision components
are returned.
2) If NI is zero or negative, no integer components are returned.
3) If the total size of the summary is greater than 125 double
precision words, some components may not be returned.
Files
None.
Particulars
The components of array summaries are packed into double
precision arrays for reasons outlined in [1]. Two routines,
DAFPS (pack summary) and DAFUS (unpack summary) are provided
for packing and unpacking summaries.
The total size of the summary is
(NI - 1)
ND + -------- + 1
2
double precision words (where ND, NI are nonnegative).
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) Use a simple routine to output the double precision and
integer values stored in an SPK's segments descriptors. This
function opens a DAF for read, performs a forwards search for
the DAF arrays, prints segments description for each array
found, then closes the DAF.
Use the SPK kernel below as input DAF file for the program.
de421.bsp
Example code begins here.
PROGRAM DAFUS_EX1
IMPLICIT NONE
C
C Define the summary parameters appropriate
C for an SPK file.
C
INTEGER MAXSUM
PARAMETER ( MAXSUM = 125 )
INTEGER ND
PARAMETER ( ND = 2 )
INTEGER NI
PARAMETER ( NI = 6 )
C
C Local variables.
C
CHARACTER*(32) KERNEL
DOUBLE PRECISION DC ( ND )
DOUBLE PRECISION SUM ( MAXSUM )
INTEGER HANDLE
INTEGER IC ( NI )
LOGICAL FOUND
C
C Open a DAF for read. Return a HANDLE referring to the
C file.
C
KERNEL = 'de421.bsp'
CALL DAFOPR ( KERNEL, HANDLE )
C
C Begin a forward search on the file.
C
CALL DAFBFS ( HANDLE )
C
C Search until a DAF array is found.
C
CALL DAFFNA ( FOUND )
C
C Loop while the search finds subsequent DAF arrays.
C
DO WHILE ( FOUND )
CALL DAFGS ( SUM )
CALL DAFUS ( SUM, ND, NI, DC, IC )
WRITE(*,*) 'Doubles:', DC(1:ND)
WRITE(*, FMT='(A,6I9)' ) 'Integers:', IC(1:NI)
C
C Check for another segment.
C
CALL DAFFNA ( FOUND )
END DO
C
C Safely close the DAF.
C
CALL DAFCLS ( HANDLE )
END
When this program was executed on a Mac/Intel/gfortran/64-bit
platform, the output was:
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 1 0 1 2 641 310404
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 2 0 1 2 310405 423048
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 3 0 1 2 423049 567372
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 4 0 1 2 567373 628976
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 5 0 1 2 628977 674740
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 6 0 1 2 674741 715224
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 7 0 1 2 715225 750428
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 8 0 1 2 750429 785632
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 9 0 1 2 785633 820836
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 10 0 1 2 820837 944040
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 301 3 1 2 944041 1521324
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 399 3 1 2 1521325 2098608
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 199 1 1 2 2098609 2098620
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 299 2 1 2 2098621 2098632
Doubles: -3169195200.0000000 1696852800.0000000
Integers: 499 4 1 2 2098633 2098644
Note, the final entries in the integer array contains the
segment start/end indexes. The output indicates the search
proceeded from the start of the file (low value index) towards
the end (high value index).
Restrictions
None.
Literature_References
None.
Author_and_Institution
J. Diaz del Rio (ODC Space)
H.A. Neilan (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
E.D. Wright (JPL)
Version
SPICELIB Version 1.1.0, 04-AUG-2020 (JDR)
Added IMPLICIT NONE statement.
Edited the header to comply with NAIF standard..
Added undeclared variables to code example.
SPICELIB Version 1.0.3, 10-OCT-2012 (EDW)
Added a functional code example to the $Examples section.
Removed the obsolete Reference citation to "NAIF
Document 167.0."
Corrected ordering of header section.
SPICELIB Version 1.0.2, 10-MAR-1992 (WLT)
Comment section for permuted index source lines was added
following the header.
SPICELIB Version 1.0.1, 22-MAR-1990 (HAN)
Literature references added to the header.
SPICELIB Version 1.0.0, 31-JAN-1990 (IMU)
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Fri Dec 31 18:36:09 2021