AIPS HELP file for SLCOL in 31DEC22
As of Tue May 30 18:48:41 2023
SLCOL: Task to collate slice data and models.
INNAME image name
INCLASS image name class
INSEQ 0.0 9999.0 image name seq #
INDISK 0.0 9.0 disk drive
name of output text file.
INVERS 0.0 46655.0 version # of first SL file.
0 => all versions
NFILES 0.0 46655.0 No. of slice files to collate
0 => 1
ZINC 0.0 4096.0 Save point every ZINC arcsecs
0 => save all slice points
PIXXY Reference position in pixels
0,0 -> use header ref pixel
OPCODE 'SLVL' and 'MODL'
' ' => 'SLVL'
APARM A(1) <=0 => don't output
slice points that are blank
A(2) >0 Overwrite existing
text file, <=0 create or
Verb: Collates SLICE file data. The output is controlled by
the opcode. Two are available:
'SLVL' : Each point in the slice is read and the distance
of that point from the reference position calculated.
SLICE_POINT_NO., X, Y, DIST, VAL
where X and Y are the distances from the header reference
pixel, DIST is the distance (arcsec) of the slice point
from the reference position, VAL is the slice point
value. The sign of DIST is set by the X distance from the
user-specified reference position; if the slice is made only in
Y, then the Y distance from PIXXY is used instead. The
SLICE_POINT_NO is just that; there are 2**n (n=7-11)
interpolated points in a slice, depending on exactly how many
image pixels it spans. The adverb ZINC enables you to save a
slice point at regular increments ALONG THE SLICE in
arcseconds, since generally you don't want all those hundreds
of slice points. If OPCODE is blank, SLVL is selected.
MODL : if Gaussian models are available, then the model
data of the LAST one will be extracted. It saves:
isl m n X Y DIST PEAK FWHM
where isl is the slice number, m is the model number, n is the
Gaussian component number, X and Y are the separations from the
reference pixel (in the header) in asec, DIST is the distance
from the user-provided PIXXY in asec, PEAK is the peak of the
model, FWHM is the width (arcsec) of the model. The same sign
convention for DIST is used. The adverbs ZINC and APARM(1) are
not used for OPCODE = 'MODL'
If you specify a disk file for output, you must include
a LOGICAL name (VMS) or an ENVIROMENT variable (UNIX).
You cannot spell out the full directory specification
or path name. This is for reasons of portability of the
VMS:OUTTEXT = 'dba1:[neil.crap]file1.dat' is NOT allowed
OUTTEXT = 'data:file1.dat' is allowed,
where `data' is
a LOGICAL name
You can define a VMS logical name at operating system
level with a command like
$ DEFINE DATA DBA1:[NEIL.CRAP]
UNIX: OUTTEXT = '/mnt/neil/crap/file1.dat' is NOT allowed
OUTTEXT = 'data:file1.dat' is allowed
where `DATA' is an
You can define an environment variable at operating
system level with a command like, for example, with the
percent setenv DATA /mnt/neil/crap
You must make sure the environment variable is upper
case, because AIPS converts everything internally to
Note also that you have the option to append to an
existing text file, or overwrite it.
Slice files are written to disk with the inverse of the
image scale and offset factors applied. Thus, the slice
and model data are scaled by SLCOL on reading. If you
rescale your image after making a slice, then SLCOL will
output the slice scaled by the new factors.
INNAME.....Input map file name (name).
INCLASS....Input map file name (class).
INSEQ......Input map file name (seq. #).
INDISK.....Disk drive # of input map file.
OUTTEXT....Name of output text file. If blank, then the output
is directed to the message terminal.
INVER......Version number of first slice file, 0 => all
NFILES.....No. of slice files to collate starting with INVERS,
0 => 1
ZINC.......Save a slice point every ZINC arcseconds along the
slice when doing 'SLVL', 0 => save all slice points
PIXXY......X,Y coordinates of a reference position (pixels)
relative to which the distances are worked out.
It is best to use the image reference pixel which you can
get by setting PIXXY(1) = PIXXY(2) = 0.000.
OPCODE.....Controls the operation
MODL : writes CEN, DIST, PEAK, POS, FWHM, ISL
SLVL : writes SL_P_NO., X, Y, DIST, VALUE,
APARM......A(1) <=0 => Do not output slice points that are
APARM......A(2) >0 => Overwrite pre-exsiting file,
else create or append.