AIPS HELP file for IN4SEQ in 31DEC25

As of Thu Nov 13 14:23:10 2025

HELP SECTION

IN4SEQ
Type: Adverb  (Real)
Use:  Data files are stored in AIPS under logical names which
      have 4 parts: a 12-character "name" field, a 6-character
      "class" field, and a numeric "sequence number" field.
      IN4SEQ is used to specify the "sequence number" field for
      the 4th of the input data files used by a verb or task.
      It is used as an integer number between 0 and 9999.
Null value:  0
      Null value means take the image having the highest
      sequence number which is consistent with the other adverb
      name parameters unless explicitly stated otherwise in the
      Help file for the verb or task.
Verbs:
   CAT4LOG.......List one or more entries in the user's data directory:
                 #4 file name.
   CLR4NAME......Clears adverbs specifying the fourth input image
   GET4NAME......Fills 4th input image name parameters by catalog slot
                 number.
   IM4HEAD.......Displays the image 4 header contents to terminal,
                 message file.
   Q4HEADER......Verb to summarize the image 4 header: positions at
                 center.
Tasks:
   BLPCL.........Do divide by I,Q,U models for circular polarization
                 BLCHN.  The 4th file is the U model.
   CMPLX.........Combines complex images by a variety of mathematical
                 methods.
   COMB..........Combines two images by a variety of mathematical
                 methods.  The 4th image is of noise for the 2nd image.
   GREYS.........Plots images as contours over multi-level grey.  The
                 4th image is for color blue.
   HOCLN.........Task to do a clean of holography images.
   IMAGR.........Wide-field and/or wide-frequency Cleaning / imaging
                 task.  The 4th image is of spectral curvature.
   KNTR..........Make a contour/grey plot file from an image w multiple
                 panels.  The 4th image is of polarization angle or U.
   MEDI..........Combines four images by a variety of mathematical
                 methods.
   OOSUB.........Subtracts/divides a model from/into a uv data base.
                 The 4th image is of spectral curvature.
   PCNTR.........Generate plot file with contours plus polarization
                 vectors.  The 4th image may be used for contours or
                 grey scale.
   PDPLT.........Plots selected contents of PD tables.
   RMFIT.........Fits 1-dimensional polarization spectrum to Q/U cube.
                 The 4th image is from FARS, either the phase or the
                 imaginary part.
   TVSPC.........Display images and spectra from a cube interactively.
                 The 4th image is an optional XYf cube to be displayed
                 one f at a time.
   VHCAL.........Do divide by I,Q,U models for linear polarization data.
   VBGLU.........Glues together data from multiple passes thru the VLBA
                 correlator.
   WTSUM.........Task to do a a sum of images weighted by other images.
                 The 4th image is of weights assigned to the 2nd image.
Procedures:
   BLPOLCAL......Do BLCHN for I, Q, U, V models.  4th is U model.
   IMFRING.......Large image delay fitting with IM2CC and OOFRING.
                 The 4th image is of spectral curvature.
   IMSCAL........Large image self-cal with IM2CC and OOCAL.
                 The 4th image is of spectral curvature.
   LINIMAGE......Build image cube from multi-IF data set.
                 The 4th image is of spectral curvature.
   OOCAL.........Determines antenna complex gain with frequency-
                 dependent models.  The 4th image is of spectral
                 curvature.
   OOFRING.......Fringe fit data to determine calibration with spectral
                 index options.  The 4th image is of spectral curvature.
   TDSTEP3.......Time-dependent imaging procedure "step 3"
   TDSTEP5.......Time-dependent imaging procedure "step 5"
   VHCALIB.......Do CALIB for linear polarization with I, Q, U models.

EXPLAIN SECTION