Table of contents
CSPICE_DASUDI updates data in a specified range of integer addresses in a
DAS file.
Given:
handle a file handle of a DAS file opened for writing.
help, handle
LONG = Scalar
first,
last the first and last of a range of DAS logical addresses of
integers to update.
help, first
LONG = Scalar
help, last
LONG = Scalar
These addresses satisfy the inequality
1 <= first <= last <= lasti
where `lasti' is the last integer logical address in
use in the DAS file designated by `handle'.
data an array of integers.
help, data
LONG = Array[N]
The array elements data[0] through data[n-1] will be written
to the indicated DAS file, where `n' is last - first + 1.
the call:
cspice_dasudi, handle, first, last, data
returns:
None.
See -Particulars for a description of the effect of this routine.
None.
Any numerical results shown for this example may differ between
platforms as the results depend on the SPICE kernels used as input
and the machine specific arithmetic implementation.
1) Write to addresses 1 through 200 in a DAS file in random-access
fashion by updating the file. Recall that data must be present
in the file before it can be updated.
Example code begins here.
PRO dasudi_ex1
;;
;; Local parameters.
;;
FNAME = 'dasudi_ex1.das'
TYPE = 'TEST'
;;
;; Open a new DAS file. Use the file name as the internal
;; file name, and reserve no records for comments.
;;
cspice_dasonw, FNAME, TYPE, FNAME, 0L, handle
;;
;; Append 200 integers to the file; after the data are
;; present, we're free to update it in any order we
;; please. (zero out an integer array.)
;;
data = lonarr( 200L )
cspice_dasadi, handle, data
;;
;; Now the integer logical addresses 1:200 can be
;; written to in random-access fashion. We'll fill them
;; in reverse order.
;;
for i=200L, 1L, -1L do begin
cspice_dasudi, handle, i, i, [i]
endfor
;;
;; Close the file.
;;
cspice_dascls, handle
;;
;; Now make sure that we updated the file properly.
;; Open the file for reading and dump the contents
;; of the integer logical addresses 1:200.
;;
cspice_dasopr, FNAME, handle
data = lonarr( 200L )
cspice_dasrdi, handle, 1L, 200L, data
print
print, 'Data from "', FNAME, '":'
print
for i=0L, 19L do begin
print, format='(10I5)', data[i*10:i*10+9]
endfor
;;
;; Close the file.
;;
cspice_dascls, handle
END
When this program was executed on a Mac/Intel/IDL8.x/64-bit
platform, the output was:
Data from "dasudi_ex1.das":
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
101 102 103 104 105 106 107 108 109 110
111 112 113 114 115 116 117 118 119 120
121 122 123 124 125 126 127 128 129 130
131 132 133 134 135 136 137 138 139 140
141 142 143 144 145 146 147 148 149 150
151 152 153 154 155 156 157 158 159 160
161 162 163 164 165 166 167 168 169 170
171 172 173 174 175 176 177 178 179 180
181 182 183 184 185 186 187 188 189 190
191 192 193 194 195 196 197 198 199 200
Note that after run completion, a new DAS file exists in the
output directory.
This routine replaces the integer data in the specified range of
logical addresses within a DAS file with the contents of the
input array `data'.
The actual physical write operations that update the indicated
DAS file with the contents of the input array `data' might not take
place before this routine returns, since the DAS system buffers
data that is written as well as data that is read. In any case,
the data will be flushed to the file at the time the file is
closed, if not earlier. A physical write of all buffered
records can be forced by calling the Icy routine cspice_daswbr
(DAS, write buffered records).
In order to append integer data to a DAS file, filling in a range
of integer logical addresses that starts immediately after the
last integer logical address currently in use, the Icy
routine cspice_dasadi (DAS add data, integer) should be used.
1) If the input file handle is invalid, an error is
signaled by a routine in the call tree of this routine.
2) Only logical addresses that already contain data may be
updated: if either `first' or `last' are outside the range
[ 1, lasti ]
where `lasti' is the last integer logical address that currently
contains data in the indicated DAS file, the error
SPICE(INVALIDADDRESS) is signaled by a routine in the call
tree of this routine. The DAS file will not be modified.
3) If first > last but both addresses are valid, this routine
will not modify the indicated DAS file. No error will be
signaled.
4) If an I/O error occurs during the data update attempted
by this routine, the error is signaled by a routine in the
call tree of this routine.
5) If any of the input arguments, `handle', `first', `last' or
`data', is undefined, an error is signaled by the IDL error
handling system.
6) If any of the input arguments, `handle', `first', `last' or
`data', is not of the expected type, or it does not have the
expected dimensions and size, an error is signaled by the Icy
interface.
7) If the data provided in `data' is insufficient to update first-last+1
integer addresses of the DAS file, an error is signaled by the Icy
interface.
See the description of the argument `handle' in -I/O.
None.
DAS.REQ
ICY.REQ
None.
J. Diaz del Rio (ODC Space)
-Icy Version 1.0.0, 16-JUL-2021 (JDR)
update integer data in a DAS file
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