Calibration table statistics (calstat)

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4.5.3 Calibration table statistics (calstat)

The calstat task will will print the statistics of solutions in a specified calibration table.

The inputs are:

#  calstat :: Displays statistical information on a calibration table
caltable            =         ’’        #  Name of input calibration table
axis                =      ’amp’        #  Which values to use
     datacolumn     =     ’gain’        #  Which data column to use

useflags            =       True        #  Take flagging into account? (not implemented)
async               =      False        #  If true the taskname must be started using calstat(...)

For example:

CASA <3>: calstat(’ngc5921.demo.gcal’,axis=’amp’,datacolumn=’gain’)
  Out[3]:
{’GAIN’: {’max’: 1.6031942367553711,
          ’mean’: 1.4448433067117419,
          ’medabsdevmed’: 0.0086394548416137695,
          ’median’: 1.5732669830322266,
          ’min’: 0.99916577339172363,
          ’npts’: 280.0,
          ’quartile’: 0.020265340805053711,
          ’rms’: 1.4650156497955322,
          ’stddev’: 0.24271160321065546,
          ’sum’: 404.55612587928772,
          ’sumsq’: 600.95579999685287,
          ’var’: 0.058908922333086665}}

CASA <4>: calstat(’ngc5921.demo.gcal’,axis=’phase’,datacolumn=’gain’)
  Out[4]:
{’GAIN’: {’max’: 0.091214209794998169,
          ’mean’: -0.015221830284565011,
          ’medabsdevmed’: 0.012778861448168755,
          ’median’: -0.012778861448168755,
          ’min’: -0.15903720259666443,
          ’npts’: 280.0,
          ’quartile’: 0.02537553571164608,
          ’rms’: 0.031241731718182564,
          ’stddev’: 0.027331476552707856,
          ’sum’: -4.2621124796782031,
          ’sumsq’: 0.27329283416317834,
          ’var’: 0.00074700961055121926}}

The statistics can be captured as return variables from the task:

CASA <7>: mystat = calstat(’ngc5921.demo.gcal’,axis=’amp’,datacolumn=’gain’)

CASA <8>: print ’Gain Amp = ’,mystat[’GAIN’][’mean’],’+/-’,mystat[’GAIN’][’stddev’]
Gain Amp = 1.44484330671 +/- 0.242711603211

ALERT: This task is still under development and currently offers no selection (e.g. by antenna) for the statistics.

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