AIPS HELP file for DESCM in 31DEC24
As of Thu Oct 10 16:41:53 2024
DESCM: Task to reduce the size of a uv data set
INPUTS
INNAME Input UV file name (name)
INCLASS Input UV file name (class)
INSEQ 0.0 9999.0 Input UV file name (seq. #)
INDISK 0.0 9.0 Input UV file disk unit #
OUTNAME Output UV file name (name)
OUTCLASS Output UV file name (class)
OUTSEQ -1.0 9999.0 Output UV file name (seq. #)
OUTDISK 0.0 9.0 Output UV file disk unit #.
BITER 0.0 9999999. First vis. to copy
NITER 0.0 9999999. Last vis. to consider.
XINC 0.0 9999. Use every XINC'th visibility
0 => 1
HELP SECTION
DESCM
Task: DESCM copies a subset of a uv data set
Adverbs:
INNAME.....Input UV file name (name). Standard defaults.
INCLASS....Input UV file name (class). Standard defaults.
INSEQ......Input UV file name (seq. #). 0 => highest.
INDISK.....Disk drive # of input UV file. 0 => any.
OUTNAME....Output UV file name (name). Standard defaults.
OUTCLASS...Output UV file name (class). Standard defaults.
OUTSEQ.....Output UV file name (seq. #). 0 => highest unique
OUTDISK....Disk drive # of output UV file. 0 => highest with
space for the file.
BITER......First visibility number to copy. 0 => 1.
NITER......Last visibility to consider. 0 => all.
XINC.......Use every XINC'th visibility 0 => 1.
EXPLAIN SECTION
DESCM: Task to reduce the size of a uv data set.
DOCUMENTOR: W. D. Cotton NRAO/C'ville.
RELATED PROGRAMS: Any of the UV tasks.
PURPOSE
DESCM is useful for making tests with large uv data sets
by reducing the size of the data set. It can also be used
with UVSRT and PRTUV to select data with desired
properties.
EXECUTION TIME:
Approximately 0.63 CPU sec per 1000 vis (both read and
written). The real time for running the task depends
on the the current load on the machine but will usually
be several times the CPU time. The times are for an otherwise
empty VAX 11-780.
DISK SPACE:
Number of blocks storage (B) on disk is:
B = V * [R + C * (3 + N)] / 128
where V = Number of visibility points
R = # of random parameters, usually 5
C = # of correlators, usually 4
N = # of channels. 1 for continuum