National Radio
Astronomy Observatory

3.5.3 Flagging command syntax

A flagging command syntax has been devised to populate the COMMAND column of the FLAG_CMD table and to direct the operation of the flagcmd task.

The syntax is similar to tflagdata, so please check help tflagdata for more info.

You can also use help flagcmd inside casapy for this syntax guide also.

Commands are a string (which may contain internal ”strings”) consisting of KEY=VALUE pairs separated by whitespace (see examples below).

NOTE: There should be no whitespace between KEY=VALUE or within each KEY or VALUE, since the simple parser first breaks command lines on whitespace, then on ”=”.

Each key should only appear once on a given command line/string

There is an implicit "mode" for each command, with the default being ’manual’ if not given.

Comment lines can start with ’#’ and will be ignored.

1. Data selection parameters (used by all flagging modes, see also §2.3)
   timerange=’’  
   antenna=’’  
   spw=’’  
   correlation=’’  
   field=’’  
   scan=’’  
   feed=’’  
   array=’’  
   uvrange=’’  
   intent=’’  
   observation=’’

   Note: a command consisting only of selection key-value pairs is a basic "manual" operation, ie. flag the data meeting the selection

2. Modes specific parameters with default values (for further details, refer to the task tflagdata, §3.4.2).
   1. Mode manual
                    autocorr=False

   2. Mode clip
   3. Mode manual
                    datacolumn=’DATA’  
                    clipminmax=[]  
                    clipoutside=True  
                    channelavg=False  
                    clipzeros=False

   4. Mode shadow
                    tolerance=0.0  
                    addantenna=’’

   5. Mode quack
                    quackinterval=0.0  
                    quackmode=’beg’  
                    quackincrement=False

   6. Mode elevation
                    lowerlimit=0.0  
                    upperlimit=90.0

   7. Mode tfcrop
                    ntime=’scan’  
                    combinescans=False  
                    datacolumn=’DATA’  
                    timecutoff=4.0  
                    freqcutoff=3.0  
                    timefit=’line’  
                    freqfit=’poly’  
                    maxnpieces=7  
                    flagdimension=’freqtime’  
                    usewindowstats=’none’  
                    halfwin=1

   8. Mode extend
                    ntime=’scan’  
                    combinescans=False  
                    extendpols=True  
                    growtime=90.0  
                    growfreq=90.0  
                    growaround=False  
                    flagneartime=False  
                    flagnearfreq=False

   9. Mode rflag
                    ntime=’scan’  
                    combinescans=False  
                    datacolumn=’DATA’  
                    winsize=3  
                    timedev=’’  
                    freqdev=’’  
                    timedevscale=5.0  
                    freqdevscale=5.0  
                    spectralmax=1000000.0  
                    spectralmin=0.0

   10. Mode unflag
3. Basic elaboration options for online and interface use
     id=’’              # flag ID tag (not necessary)  
     reason=’’          # reason string for flag  
     flagtime=’’        # a timestamp for when this flag was generated (for  
                          user history use)

   NOTE: there is no flagtime column in FLAG_CMD at this time, but we will propose to add this as an optional column

   NOTE: These are currently ignored and not used

4. Extended elaboration options for online and interface use Note: these are FLAG_CMD columns, but their use is not clear but included here for compatibility and future expansion
     level=N            # flagging "level" for flags with same reason  
     severity=N         # Severity code for the flag, on a scale of 0-10 in order  
                          of increasing severity; user specified

More information about CASA may be found at the CASA web page

Copyright © 2010 Associated Universities Inc., Washington, D.C.

This code is available under the terms of the GNU General Public Lincense