AIPS HELP file for FGDIF in 31DEC22
As of Sat Sep 23 11:25:26 2023
FGDIF: Compares the affect of two FG tables
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 #
SOURCES Restrict to listed sources
CALCODE Calibrator code ' ' all
FLAGVER 1st Flag table version
INVERS 2nd Flag table version
CPARM (1) Time interval in sec
Important - see HELP.
(2) > 0 limit to those flags
that REFLG uses
(3) > 0 => print differences
in IF = CPARM(3)
(4) max number messages from
CPARM(3) request 0 -> 100
BADDISK Disks to avoid for scratch
Task: Compares the consequences of 2 flag tables to see if there are
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.
SOURCES....List of sources to for which flags are reviewed. The
task has to list all times for a source and check them
against the flags. Preparing the list of times can be
expensive so this adverb lets you avoid sources which are
not relevant to the flag table. '*' or ' ' = all; a "-"
before a source name means all except ANY source named.
CALCODE....Also used to limit sources selected: '*' => any
non-blank, '-CAL' => only blank, ' ' => all, otherwise
FLAGVER....Specifies the version of the 1st flagging table to be
compared. <= 0 => highest numbered table
INVERS.....The 2nd flagging table to be compared. <= 0 =>
highest but not the same as FLAGVER.
CPARM......(1) Normal interval between samples (IMPORTANT) in sec.
Use a little bit less than the normal interval.
0 -> 10. This parameter can have interesting and
confusing consequences when data have been time
averaged by say UVAVG. Let us assume you have
averaged 1 second data with no flags to 5 seconds and
that the data started at time 0. Thenthe average
times will be 2, 7, 12, 17, etc seconds. But at the
end of the scan (e.g. time 20) there could be onl;y
one 1-sec record so its averaged time would be 20.
Thus to separate the 17 and the 20 one must set
CPARM(1) = 2.9 say. However, if the data input to
UVAVG already have extensive flagging, the times may
be disturbed from this nice pattern (depnding on
OPCODE in UVAVG). In this case, the possibilities
are endless and there is no simple answer to a
correct value for CPARM(1). (One might consider TIME
or even GRID in UVAVG to alleviate this issue.) The
simplest thing to do in the heavy editing case might
be to set CPARM(1) = 0.95 at least in FGDIF.
(2) > 0 => limit the testing to flag records that apply
to one baseline, fewer than all IFs, and fewer than
all channels. Else include all flags.
(3) > 0 => print the differences in detail for IF =
(4) If CPARM(3) > 0, CPARM(4) is the maximum number of
detailed differences that will be printed. 0 -> 100.
BADDISK....The disk numbers to avoid for scratch files (sorting