AIPS NRAO AIPS HELP file for NCOMP in 31DEC25



As of Wed Dec 11 5:13:42 2024



HELP SECTION

NCOMP
Type: Adverb   (Real(64))
Use:  NCOMP is a general adverb to express an array of maximum values,
      usually the maximum number of Clean components to process for each
      of up to 64 fields.
Null value:  0
      Null value assignment varies with task or verb, usually 0 ->
      all.

For calibration image modeling, NCOMP is the number of Clean
components to use for the model, one value per field.  If all values
are zero, then all components in all fields are used.  If any value is
not zero, then abs(NCOMP(i)) (or fewer depending on FLUX and
negativity) components are used for field i, even if NCOMP(i) is zero.
If any of the NCOMP is less than 0, then components are only used in
each field i up to abs(NCOMP(i)), FLUX, or the first negative
whichever comes first.  If abs(NCOMP(i)) is greater than the number of
components in field i, the actual number is used.  For example
                   NCOMP = -1,0
says to use one component from field one unless it is negative or <
FLUX and no components from any other field.  This would usually not
be desirable.
                   NCOMP = -1000000
says to use all components from each field up to the first negative in
that field.
                   NCOMP = -200 100 23 0 300 5
says to use no more than 200 components from field 1, 100 from field
2, 23 from field 3, 300 from field 5, 5 from field 6 and none from any
other field.  Fewer are used if a negative is encountered or the
components go below FLUX.
Tasks:
   BLCAL......Compute closure offset corrections.
   BLCHN......Compute closure offset corrections on a channel-by-channel
              basis.
   BLING......Find residual rate and delay on individual baselines,
   BPASS......Computes spectral bandpass correction table.
   CALIB......Determines antenna calibration: complex gain.
   CAPLT......Plots closure amplitude and model from CC file,
   CLPLT......Plots closure phase and model from CC file,
   CPASS......Computes polynomial spectral bandpass correction table.
   EVAUV......Subtracts & divides a model into UV data, does statistics
              on results.
   FRING......Fringe fit data to determine antenna calibration, delay,
              rate.
   IBLED......Interactive BaseLine based visibility EDitor.
   KRING......Fringe fit data to determine antenna calibration, delay,
              rate.
   LPCAL......Determines instrumental polarization for UV data.
   MOD3D......Computes a 3D CC model from a set of facets.
   OOSUB......Subtracts/divides a model from/into a uv data base.
   PCAL.......Determines instrumental polarization for UV data.
   RLCAL......Determines instrumental right-left phase versus time (a
              self-cal).
   UVADC......Fourier transforms and corrects a model and adds to uv
              data.
   UVCON......Generate sample UV coverage given a user defined array
              layout.
   UVSUB......Subtracts/divides a model from/into a uv data base.
   VPLOT......Plots uv data and model from CC file.
Procedures:
   IMSCAL.....Large image self-cal with IM2CC and OOCAL.
   OOCAL......Determines antenna complex gain with frequency-dependent
              models.
   OOFRING....Fringe fit data to determine calibration with spectral
              index options.
   VLBABPSS...Computes spectral bandpass correction table.

EXPLAIN SECTION


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