AIPS HELP file for TX2IM in 31DEC26

As of Wed May 20 1:59:39 2026

INPUTS

OUTNAME                            Input image name (name)
OUTCLASS                           Input image name (class)
OUTSEQ            0.0     9999.0   Input image name (seq. #)
OUTDISK           0.0        9.0   Input image disk unit #
INFILE
                                   Input file name
AXTYPE                             Axis type of 1st output axis
COORDINA                           RA, Dec in sexagesimal
REFREQ                             Reference frequency in GHz
SRCNAME                            Source name
REFDATE                            Observation date 'yyyymmdd'

HELP SECTION

TX2IM
Task: Converts a one dimensional text file into an 1-D cataloged image.
      It is happiest with the output of IM2TX but other text files may
      be given with the adverbs providing the necessary header info.
Adverbs:
  OUTNAME.....Input image name (name).       Standard defaults.
  OUTCLASS....Input image name (class).      Standard defaults.
  OUTSEQ......Input image name (seq. #).     0 => highest.
  OUTDISK.....Disk drive # of input image.   0 => any.
  INFILE......Input text file.  The usual form is given by a logical,
              then a colon, and then the file name.  'MYDISK:myfile
              without a trailing quote to allow lowercase letters.
  AXTYPE......String identifying the "X" axis type if not in INFILE.
  COORDINA....Right ascension and declination to use if not in INFILE.
  REFREQ......Reference frequency in GHz to use if not in INFILE.
  SRCNAME.....Source name (only first 8 characters appear in header)
  REFDATE.....Date of observation 'yyyymmdd'

EXPLAIN SECTION

A sample INFILE which is the output of IM2TX is:

#Data type 3 'FREQ    '
#INFO BUNIT 'JY/BEAM '  OBSDATE '19960227'
#INFO SRCNAME 'NGC6503 '
#INFO ALTCODE      2
#INFO ALTVAL  2.600000E+04 ALTPIX   54.0
#INFO RESTFREQ  1.420406E+09
#HEADa 1  'RA---SIN' Npts   317 BLC/TRC   162.   170.
#HEADb 1  Refval  2.6725000E+02  Cdelt -1.111111E-03
#HEADc 1  Refpix   178.0
#HEADd 1  AvgValue  2.672892308E+02
#HEADa 2  'DEC--SIN' Npts   179 BLC/TRC    74.    85.
#HEADb 2  Refval  7.0116667E+01  Cdelt  1.111111E-03
#HEADc 2  Refpix    67.0
#HEADd 2  AvgValue  7.013110682E+01
#HEADa 3  'FREQ    ' Npts   108 BLC/TRC     1.   108.
#HEADb 3  Refval  1.4202759E+09  Cdelt  2.441406E+04
#HEADc 3  Refpix    54.0
#HEADd 3  AvgValue  1.420288109E+09
#HEADa 4  'STOKES  ' Npts     1 BLC/TRC     1.     1.
#HEADb 4  Refval  1.0000000E+00  Cdelt  1.000000E+00
#HEADc 4  Refpix     1.0
  1.418981956E+09    2.121160E-03
  1.419006370E+09   -1.628731E-02
  1.419030784E+09   -1.811423E-02
  1.419055199E+09    3.892953E-04
  1.419079613E+09    2.113613E-02
  1.419104027E+09    1.194823E-02
  1.419128441E+09   -2.353090E-02
  1.419152855E+09    1.362888E-02
  1.419177269E+09   -2.743865E-03
  1.419201683E+09   -1.984505E-02
...

Lines beginning with # are viewed as comments except as above.
The first column of numbers gives the "X" coordinate of the
1-D image and the second column gives the data value.  These
two columns are in free format.  In this example the FQID axis
is the "X" axis and all of the other axes will appear at their
average value.

TX2IM parses this file in a free-format fashion.  If the text
file line begins with #Data it looks for a string in ' marks
and takes it to be the type of axis 1 in the output.  If the
text line begins with #INFO it looks for keywords BUNIT, OBSDATE,
and SRCNAME and captures the string enclosed in ' marks
following each keyword for the corresponding strings in the
output header.  Adverb SRCNAME is the default value for SRCNAME
and adverb REFDATE is the default for OBSDATE.  The default for
BUNIT is 'JY/BEAM'.  Additional #INFO lines provide the
alternative frequency/velocity axis information if the parameters
were known to the header in IM2TX and the output 1D axis was
FREQ.  These are ALTCODE, ALTVAL, ALTPIX, and RESTFREQ.  All of
these have 0 as default and real values for all are needed for
the ALTSWTCH verb to work.

If the text line begins with #HEAD, TX2IM finds the axis number
following the first blank.  Then it looks for a string enclosed
in ' marks to be an axis type.  It also looks for keywords
AvgValue, Cdelt, and Refval and captures the value following them.
For the 1-pixel output axes, the coordinate reference value is set
to AvgValue if present or Refval if not.  COORDINA provides
reference values for RA and DEC axes if both of these are absent.

If the #HEAD portion is missing then TX2IM will add RA, DEC,
FREQ, and STOKES one-pixel axes.