| dlabns |
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Table of contents
Procedure
DLABNS ( DLA, begin new segment )
SUBROUTINE DLABNS ( HANDLE )
Abstract
Begin a new segment in a DLA file.
Required_Reading
DAS
DLA
Keywords
DAS
DLA
FILES
Declarations
IMPLICIT NONE
INCLUDE 'dla.inc'
INTEGER HANDLE
Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
HANDLE I Handle of open DLA file.
Detailed_Input
HANDLE is the integer handle associated with the DLA file to
be updated. This handle is used to identify the file
in subsequent calls to other DLA or DAS routines.
The DLA file must be open for write access. A new DLA
segment is started in the indicated file. The file
is left open, since normally data will be written to
the file following a call to this routine.
Detailed_Output
None. See the $Particulars and $Examples header sections for
a description of the actions performed by this routine.
Parameters
None.
Exceptions
1) If the input file handle does not refer to a DAS file that is
open for write access, an error is signaled by a routine
in the call tree of this routine.
2) If an error occurs while reading or writing to the DLA file,
the error is signaled by a routine in the call tree of
this routine.
Files
See description of input argument HANDLE.
Particulars
DLA files are built using the DAS low-level format; DLA files are
a specialized type of DAS file in which data are organized as a
doubly linked list of segments. Each segment's data belong to
contiguous components of character, double precision, and integer
type.
This routine supports creation of a DLA segment. DLA segments
are created by appending data to the DAS integer, double
precision, and character address spaces of a DLA file. The new
segment's descriptor is located immediately before the integer
component of the segment's data.
When a new segment is added to a DLA file, the segment is
inserted into the file's doubly linked segment list. If the new
segment is the first, the DLA file's first and last list entry
pointers are updated to point to the new segment; specifically,
these pointers point to the first integer of the new segment's
descriptor. The backward pointer of the new segment is set to
null in this case.
If the new segment is not the first, the DLA file's list end
pointer is updated to point to the new segment, and the forward
pointer of the previous segment also is updated to point to the
first integer of the new segment's descriptor. The backward
pointer of the new segment points to the first integer of the
previous segment's descriptor.
The normal sequence of operations required to create a DLA
segment is as follows:
Call DLAOPN to create a new, empty DLA file.
For each segment to be created,
Call DLABNS to begin a segment.
Use the DAS "add" and "update" routines to populate
the segment with data.
Call DLAENS to end the segment.
Call DASCLS to segregate and close the DLA file.
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) Create a DLA file containing one segment; the segment
contains character, double precision, and integer data.
After writing and closing the file, open the file for
read access; dump the data to standard output.
Example code begins here.
PROGRAM DLABNS_EX1
IMPLICIT NONE
INCLUDE 'dla.inc'
C
C Local parameters
C
CHARACTER*(*) DLA
PARAMETER ( DLA = 'dlabns_ex1.dla' )
INTEGER IFNLEN
PARAMETER ( IFNLEN = 60 )
INTEGER LNSIZE
PARAMETER ( LNSIZE = 61 )
INTEGER MAXC
PARAMETER ( MAXC = 5 )
INTEGER MAXD
PARAMETER ( MAXD = 50 )
INTEGER MAXI
PARAMETER ( MAXI = 100 )
C
C Local variables
C
CHARACTER*(LNSIZE) CVALS ( MAXC )
CHARACTER*(LNSIZE) CVALS2 ( MAXC )
CHARACTER*(IFNLEN) IFNAME
DOUBLE PRECISION DVALS ( MAXD )
DOUBLE PRECISION DVALS2 ( MAXD )
INTEGER BASE
INTEGER DESCR ( DLADSZ )
INTEGER HANDLE
INTEGER I
INTEGER IVALS ( MAXI )
INTEGER IVALS2 ( MAXI )
INTEGER J
INTEGER K
INTEGER N
INTEGER NCOMCH
LOGICAL FOUND
C
C Set the internal file name. Don't reserve characters in
C the DAS comment area.
C
IFNAME = 'Example DLA file for testing'
NCOMCH = 0
C
C Open a new DLA file.
C
CALL DLAOPN ( DLA, 'DLA', IFNAME, NCOMCH, HANDLE )
C
C Begin a new segment.
C
CALL DLABNS ( HANDLE )
C
C Add character data to the segment.
C
DO I = 1, MAXC
DO J = 1, LNSIZE
K = MOD( J+I-1, 10 )
CALL INTSTR ( K, CVALS(I)(J:J) )
END DO
END DO
CALL DASADC ( HANDLE, MAXC*LNSIZE, 1, LNSIZE, CVALS )
C
C Add integer and double precision data to the segment.
C
DO I = 1, MAXI
IVALS(I) = I
END DO
CALL DASADI ( HANDLE, MAXI, IVALS )
DO I = 1, MAXD
DVALS(I) = I
END DO
CALL DASADD ( HANDLE, MAXD, DVALS )
C
C End the segment.
C
CALL DLAENS ( HANDLE )
C
C Close the file. The routine DASCLS flushes the DAS
C buffers and segregates the file before closing it.
C
CALL DASCLS ( HANDLE )
C
C Now read the file and check the data.
C
CALL DASOPR ( DLA, HANDLE )
C
C Obtain the segment descriptor for the sole segment
C in the file. We need not check the found flag
C in this case because we know there is one segment
C in the file.
C
CALL DLABFS ( HANDLE, DESCR, FOUND )
C
C Fetch character data from the segment. Obtain the
C base address of the character data and the
C character count from the descriptor.
C
BASE = DESCR(CBSIDX)
N = DESCR(CSZIDX)
CALL DASRDC ( HANDLE, BASE+1, BASE+N, 1, LNSIZE, CVALS2 )
C
C Display the character data.
C
WRITE (*,*) ' '
WRITE (*,*) 'Character array:'
DO I = 1, N/LNSIZE
WRITE (*,*) CVALS2(I)
END DO
C
C Fetch and display the integer and double precision data.
C
BASE = DESCR(IBSIDX)
N = DESCR(ISZIDX)
CALL DASRDI( HANDLE, BASE+1, BASE+N, IVALS2 )
WRITE (*,*) ' '
WRITE (*,*) 'Integer array:'
DO I = 1, N/10
WRITE (*,'(10I6)') (IVALS2((I-1)*10 + J), J=1, 10)
END DO
BASE = DESCR(DBSIDX)
N = DESCR(DSZIDX)
CALL DASRDD( HANDLE, BASE+1, BASE+N, DVALS2 )
WRITE (*,*) ' '
WRITE (*,*) 'Double precision array:'
DO I = 1, N/10
WRITE (*,'(10F6.1)') (DVALS2((I-1)*10 + J), J=1, 10)
END DO
C
C Close the file. This step is unnecessary in this
C program, but is a good practice in general
C because closing the file frees resources.
C
CALL DASCLS ( HANDLE )
END
When this program was executed on a Mac/Intel/gfortran/64-bit
platform, the output was:
Character array:
1234567890123456789012345678901234567890123456789012345678901
2345678901234567890123456789012345678901234567890123456789012
3456789012345678901234567890123456789012345678901234567890123
4567890123456789012345678901234567890123456789012345678901234
5678901234567890123456789012345678901234567890123456789012345
Integer array:
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
Double precision array:
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
Note that after run completion, a new DLA file exists in the
output directory.
Restrictions
None.
Literature_References
None.
Author_and_Institution
N.J. Bachman (JPL)
J. Diaz del Rio (ODC Space)
Version
SPICELIB Version 1.0.1, 14-JUN-2021 (JDR)
Edited the header to comply with NAIF standard. Modified
the presentation of the output in the code example to comply
with the maximum line length for the header comments.
SPICELIB Version 1.0.0, 08-FEB-2017 (NJB)
Updated version info.
13-JUL-2012 (NJB)
Bug fix: deleted unused line of code.
Fixed some header typos.
08-OCT-2009 (NJB)
Updated header.
11-FEB-2005 (NJB)
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Fri Dec 31 18:36:13 2021