; EIF
;---------------------------------------------------------------
;! last IF (spectral window) number to be included in operation
;# ADVERB UV
;-----------------------------------------------------------------------
;;  Copyright (C) 1995, 2020
;;  Associated Universities, Inc. Washington DC, USA.
;;
;;  This program is free software; you can redistribute it and/or
;;  modify it under the terms of the GNU General Public License as
;;  published by the Free Software Foundation; either version 2 of
;;  the License, or (at your option) any later version.
;;
;;  This program is distributed in the hope that it will be useful,
;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;  GNU General Public License for more details.
;;
;;  You should have received a copy of the GNU General Public
;;  License along with this program; if not, write to the Free
;;  Software Foundation, Inc., 675 Massachusetts Ave, Cambridge,
;;  MA 02139, USA.
;;
;;  Correspondence concerning AIPS should be addressed as follows:
;;         Internet email: aipsmail@nrao.edu.
;;         Postal address: AIPS Project Office
;;                         National Radio Astronomy Observatory
;;                         520 Edgemont Road
;;                         Charlottesville, VA 22903-2475 USA
;-----------------------------------------------------------------------
;---------------------------------------------------------------
EIF       LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
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EIF
Type:  Adverb  (scalar)
Use:   Standard data selection adverb, used to specify the highest IF
       (or spectral window) be included.  An IF consists of a set of
       one or more equally spaced frequency channels; multiple IFs with
       arbitrary frequency spacings are allowed.
Null value:
       0   => highest numbered IF in data.
Verbs:
   OBITIMAG......Access to OBIT task Imager without self-cal or peeling.
   OBITMAP.......Simplified access to OBIT task Imager.
   OBITPEEL......Access to OBIT task Imager with self-cal and peeling.
   OBITSCAL......Access to OBIT task Imager with self-cal, NOT peeling.
   SIZEFILE......Return file size plus estimate of IMAGR work file size.
Procedures:
   CXIMAGR.......Grid UV data into a complex image, Fourier transform,
                 Clean.
   CXPOLN........Procedure to make complex polarization images and beam.
   DOVLAMP.......Produces amp calibration file for phased-VLA VLBI data.
   IMFRING.......Large image delay fitting with IM2CC and OOFRING.
   LINIMAGE......Build image cube from multi-IF data set.
   MAPPR.........Simplified access to IMAGR.
   OOFRING.......Fringe fit data to determine calibration with spectral
                 index options.
Tasks:
   ACLIP.........Edits suto-corr data for amplitudes, phases, and weights
                 out of range.
   ALVAR.........Plots the Allan Variance statistic of a UV data set.
   ALVPR.........Prints statistics on the Allan Variance of a UV data set.
   ANBPL.........Plots and prints uv data converted to antenna based
                 values.
   APCAL.........Apply TY and GC tables to generate an SN table.
   ATMCA.........Determines delay/phase gradient from calibrator
                 observations.
   AVSPC.........Averages uv-data in the frequency domain.
   BLAVG.........Average cross-polarized UV data over baselines.
   BLING.........Find residual rate and delay on individual baselines.
   BLPLT.........Plots BLCAL tables in 2 dimensions as function of
                 baseline and IF.
   BPCOR.........Correct BP table.
   BPEDT.........Interactive TV task to edit uv data based on BP tables.
   BPEPL.........Plots bandpass tables overlaying multiple times like
                 BPEDT.
   BPFLG.........Flgas uv data based on bad BP values.
   BPLOT.........Plots bandpass tables in 2 dimensions as function of
                 time.
   BPWAY.........Determines channel-dependent relative weights.
   BPWGT.........Calibrates data and scales weights by bandpass
                 correction.
   BSCAN.........Seeks best scan to use for phase cal, fringe search, ..
   CAPLT.........Plots closure amplitude and model from CC file.
   CLCOR.........Applies user-selected corrections to the calibration CL
                 table.
   CLIP..........Edits data based on amplitudes, phases, and weights out
                 of range.
   CLPLT.........Plots closure phase and model from CC file.
   CLSMO.........Smooths a calibration CL table.
   CORER.........Calculates correlator statistics and flags bad ones.
   CPASS.........Computes polynomial spectral bandpass correction table.
   CSCOR.........Applies specified corrections to CS tables.
   DECOR.........Measures the decorrelation between channels and IF of uv
                 data.
   DEFLG.........Edits data based on decorrelation over channels and time.
   DELZN.........Determines residual atmosphere depth at zenith and clock
                 errors.
   DFCOR.........Applies user-selected corrections to the calibration CL
                 table.
   DFTIM.........Makes image of DFT at arbitrary point showing time vs
                 frequency.
   DFTPL.........Plots DFT of a UV data set at arbitrary point versus
                 time.
   DIFRL.........Divides the RR data by LL data.
   DTSUM.........Task to provide a summary of the contents of a dataset.
   EDITA.........Interactive TV task to edit uv data based on TY/SY/SN/CL
                 tables.
   EDITR.........Interactive baseline-oriented visibility editor using the
                 TV.
   ELFIT.........Plots/fits selected contents of SN, TY, SY, PC or CL
                 files.
   ELINT.........Determines and removes gain dependence on elevation.
   EVASN.........Evaluates statistics in SN/CL tables.
   EVAUV.........Subtracts & divides a model into UV data, does statistics
                 on results.
   FGCNT.........Counts samples comparing two flag tables.
   FGPLT.........Plots selected contents of FG table.
   FGPRT.........Pprints counts of selected portions of an FG table.
   FGSPW.........Flags bad spectral windows.
   FILLR.........Reads old VLA on-line-system tapes into AIPS.
   FINDR.........Find normal values for a uv data set.
   FITLD.........Reads FITS files to load images or UV (IDI or UVFITS)
                 data to disk.
   FLAGR.........Edit data based on internal RMS, amplitudes, weights.
   FLGIT.........Flags data based on the rms of the spectrum.
   FLOPM.........Reverses the spectral order of UV data, can fix VLA
                 error.
   FRING.........Fringe fit data to determine antenna calibration, delay,
                 rate.
   FRPLT.........Task to plot fringe rate spectra.
   FTFLG.........Interactive flagging of UV data in channel-time using the
                 TV.
   FUDGE.........Modifies UV data with user's algorithm: paraform task.
   GETJY.........Determines calibrator flux densities.
   IBLED.........Interactive BaseLine based visibility EDitor.
   IMAGR.........Wide-field and/or wide-frequency Cleaning / imaging task.
   KRING.........Fringe fit data to determine antenna calibration, delay,
                 rate.
   LISTR.........Prints contents of UV data sets and assoc. calibration
                 tables.
   LOCIT.........Fits antenna locations from SN-table data.
   LPCAL.........Determines instrumental polarization for UV data.
   MAPBM.........Map VLA beam polarization.
   MBDLY.........Fits multiband delays from IF phases, updates SN table.
   MORIF.........Combines IFs or breaks spectral windows into multiple
                 windows (IFs).
   NOIFS.........Makes all IFs into single spectrum.
   OMFIT.........Fits sources and, optionally, a self-cal model to uv
                 data.
   OOSUB.........Subtracts/divides a model from/into a uv data base.
   OTFBS.........Translates on-the-fly continuum SDD format to AIPS UV
                 file.
   OTFUV.........Translates on-the-fly single-dish SDD format to AIPS UV
                 file.
   PCAL..........Determines instrumental polarization for UV data.
   PCCOR.........Corrects phases using  PCAL tones data from PC table.
   PCEDT.........Interactive TV task to edit pulse-cal (PC) tables.
   PCFLG.........Interactive flagging of Pulse-cal data in channel-TB
                 using the TV.
   PCPLT.........Plots pulse-cal tables in 2 dimensions as function of
                 time.
   PDPLT.........Plots selected contents of PD tables.
   PLOTC.........Plots color schems used by 3-color plot tasks.
   POSSM.........Task to plot total and cross-power spectra.
   QUACK.........Flags beginning or end portions of UV-data scans.
   RFI...........Look for RFI in uv data.
   RFLAG.........Flags data set based on time and freq rms in fringe
                 visibilities.
   RLCAL.........Determines instrumental right-left phase versus time (a
                 self-cal).
   RLCOR.........Corrects a data set for R-L phase differences.
   RLDIF.........Determines Right minus Left phase difference, corrects
                 cal files.
   RLDLY.........Fringe fit data to determine antenna R-L delay
                 difference.
   SDCAL.........Task to apply single dish calibration.
   SDMOD.........Modifies single-dish UV data with model sources.
   SETJY.........Task to enter source info into source (SU) table.
   SHOUV.........Displays uv data in various ways.
   SNBLP.........Plots selected contents of SN or CL files on a baseline
                 basis.
   SNCOR.........Applies user-selected corrections to the calibration SN
                 table.
   SNEDT.........Interactive SN/CL/TY/SY table editor using the TV.
   SNFIT.........Fits parabola to SN amplitudes and plots result.
   SNFLG.........Writes flagging info based on the contents of SN files.
   SNIFS.........Plots selected contents of SN, TY, SY, PC or CL files by
                 IF.
   SNPLT.........Plots selected contents of SN, SY, TY, PC or CL files
                 versus time.
   SNSMO.........Smooths and filters a calibration SN table.
   SOLCL.........Adjust gains for solar data according to nominal
                 sensitivity.
   SPFLG.........Interactive flagging of UV data in channel-TB using the
                 TV.
   SPLAT.........Applies calibration and splits or assemble selected
                 sources.
   SPLIT.........Converts multi-source to single-source UV files w
                 calibration.
   SPMOD.........Modify UV database by adding a model with spectral lines.
   SPRMS.........Plots spectral statistics of a selected subset of a uv
                 data set.
   SUFIX.........Modifies source numbers on uv data.
   SYPRT.........Task to print values from the SY table.
   TI2HA.........Modifies times in UV data to hour angles.
   TIORD.........Checks data for time baseline ordering, displays
                 failures.
   TRUEP.........Determines true antenna polarization from special data
                 sets.
   TVFLG.........Interactive flagging of UV data using the TV.
   TYSMO.........Smooths and filters a calibration TY or SY table.
   UFLAG.........Plots and edits data using a uv-plane grid and the TV.
   UV2MS.........Append single-source file to multi-source file.
   UV2TB.........Converts UV autocorrelation spectra to tables.
   UVADC.........Fourier transforms and corrects a model and adds to uv
                 data.
   UVAVG.........Average or merge a sorted (BT, TB) uv database.
   UVBAS.........Averages several channels and subtracts from uv data.
   UVCOP.........Task to copy a subset of a UV data file.
   UVFIT.........Fits source models to uv data.
   UVFLG.........Flags UV-data.
   UVGIT.........Fits source models to uv data.
   UVHGM.........Plots statistics of uv data files as histogram.
   UVHIM.........Makes image of the histogram on two user-chosen axes.
   UVIMG.........Grid UV data into an "image".
   UVLIN.........Fits and removes continuum visibility spectrum, also can
                 flag.
   UVLSD.........Least squares fit to channels and divides the uv data.
   UVLSF.........Least squares fit to channels and subtracts from uv data.
   UVMLN.........Edits data based on the rms of the spectrum.
   UVMOD.........Modify UV database by adding a model incl spectral index.
   UVPLT.........Plots data from a UV data base in multiple ways.
   UVRFI.........Mitigate RFI by Fourier transform or fitting the circle.
   UVRMS.........Computes statistics of a selected subset of a uv data
                 set.
   UVSUB.........Subtracts/divides a model from/into a uv data base.
   VPLOT.........Plots uv data and model from CC file.
   WIPER.........Plots and edits data from a UV data base using the TV.
   XYDIF.........Find/apply X minus Y linear polarization phase
                 difference.
   XYMOD.........Compute linear polarization point source model, applies
                 to data.
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