accum Namespace Reference

Functions
def	accum

---

Function Documentation

def accum.accum	(		vis = '',
			tablein = '',
			incrtable = '',
			caltable = '',
			field = [''],
			calfield = [''],
			interp = 'linear',
			accumtime = 1.0,
			spwmap = [-1]
	)

Accumulate incremental calibration solutions into a calibration table

       Accum will interpolate and extrapolate a temporal calibration
       table onto a new table that has a regularly-space time grid.

       The first run of accum defines the time grid and fills this
       table with the results from the input table.

       Subsequent use of accum will combine additional calibration
       tables onto the same grid of the initial accum table to obtain
       an output accum table.  See below for a concrete example.


     Keyword arguments:

     vis -- Name of input visibility file
     default: none.  example: vis='ngc5921.ms'
     tablein -- Input cumulative calibration table.
     default: ''  means none
     On first execution of accum, tablein=''
     and accumtime is used to generate tablein with
     the specified time gridding.
     accumtime -- The time separation when making tablein.
     default: 1.0  (1 second).  This time should not be
     less than the visibiility sampling time, but should
     be less than about 30% of a typical scan length.
     incrtable -- The calibration data to be interpolated onto the
     tablein file.
     default: ''.  Must be specified
     caltable -- The output cumulated calibration file.
     default: ''  means use tablein as the output file
     
     field -- Select field(s) from tablein to process.
      ['go listobs' to obtain the list id's or names]
    default: ''= all fields
    If field string is a non-negative integer, it is assumed to
       be a field index otherwise, it is assumed to be a field name
    field='0~2'; field ids 0,1,2
    field='0,4,5~7'; field ids 0,4,5,6,7
    field='3C286,3C295'; field named 3C286 and 3C295
    field = '3,4C*'; field id 3, all names starting with 4C
     calfield -- Select field(s) from incrtable to process.
    default: '' = all fields
     interp -- Interpolation type (in time[,freq]) to use for each gaintable.
        When frequency interpolation is relevant (B, Df, Xf),
        separate time-dependent and freq-dependent interp
        types with a comma (freq _after_ the comma).                
        Specifications for frequency are ignored when the
        calibration table has no channel-dependence.
        Time-dependent interp options ending in 'PD' enable a
        "phase delay" correction per spw for non-channel-dependent
        calibration types.
        default: '' --> 'linear,linear' for all gaintable(s)
        example: interp='nearest'   (in time, freq-dep will be
                                     linear, if relevant)
                 interp='linear,cubic'  (linear in time, cubic
                                         in freq)
                 interp=',spline'  (spline in freq; linear in
                                    time by default)
                 interp=['nearest,spline','linear']  (for multiple gaintables)
        Options: Time: 'nearest', 'linear'
                 Freq: 'nearest', 'linear', 'cubic', 'spline'
     spwmap -- Spectral windows combinations to form for gaintable(s)
    default: [] (apply solutions from each spw to that spw only)
    Example:  spwmap=[0,0,1,1] means apply the caltable solutions
              from spw = 0 to the spw 0,1 and spw 1 to spw 2,3.
              spwmap=[[0,0,1,1],[0,1,0,1]]  (for multiple gaintables)
     async -- Run task in a separate process 
     default: False; example: async=True

     Examples:

       Create an accum table with 10-sec sampling, filling it with the calibration
  in 'first_cal' with the desired interpolation.

   taskname = 'accum'
     default()
     vis = 'mydata.ms'
     tablein = ''
     accumtime = 10
     incrtable = 'first_cal'
     caltable = 'accum1_cal'
     accum()

       If you plot 'accum1_cal' with plotcal, you can see how the incrtable was
     interpolated.

       Continue accumulating calibrations in accum1_cal from 'second_cal'

   taskname = 'accum'
     default()
     vis = 'mydata.ms'
     tablein = 'accum1_cal'
     incrtable = 'second_cal'
     caltable = 'accum1_cal'
     accum()

       Incorporate gaincurve, opacity, parang once and for all

  taskname= 'gaincal'
     vis = 'mydata.ms'
     caltable = 'first_cal'
       etc
     gaincurve = T
     opacity = 0.11
     parang = T
     gaincal()

   taskname = 'accum'
     default()
     vis = 'mydata.ms'
     tablein = ''
     accumtime = 10
     incrtable = 'first_cal'
     caltable = 'accum1_cal'
     accum()

 accum1_cal with contain not only the gaincal solution, but the gaincurve,
     opacity and parang correction.  Hence, when applying accum1_cal
     on the fly for subsequent calibrations (gaincal, bandpass) or applying
     the calibrations, then
        gaincurve=F; opacity = 0.0; parang = F  should be used

Definition at line 13 of file accum.py.

References task_accum.accum(), and vla_uvfits_line_sf.verify.