Provided by: funtools_1.4.7-2_amd64 bug

NAME

       funsky - convert between image and sky coordinates

SYNOPSIS

       funsky iname[ext]               # RA,Dec (deg) or image pix from stdin
       funsky iname[ext] [lname]       # RA, Dec (deg) or image pix from list
       funsky iname[ext] [col1] [col2]         # named cols:units from stdin
       funsky iname[ext] [lname] [col1] [col2] # named cols:units from list

OPTIONS

         -d        # always use integer tlmin conversion (as ds9 does)
         -r        # convert x,y to RA,Dec (default: convert RA,Dec to x,y)
         -o        # include offset from the nominal target position (in arcsec)
         -v        # display input values also (default: display output only)
         -T        # output display in rdb format (w/header,tab delimiters)

DESCRIPTION

       Funsky converts input sky coordinates (RA, Dec) to image coordinates (or vice versa) using
       the WCS information contained in the specified FITS file. Several calling sequences are
       supported in order to make it easy to specify coordinate positions in different ways.

       The first required argument is always the input FITS file (or extension) containing the
       WCS information in an extension header. Note that the data from this file is not used. By
       default, the program converts input RA and Dec values to X and Y using this WCS
       information. If the WCS is associated with a FITS image, then the X,Y values are image
       values. If the WCS is associated with a binary table, then the X, Y values are physical
       values.  To convert X,Y to RA and Dec, use the -r (reverse) switch.

       If no other command arguments are supplied, then the input positions are read from the
       standard input. Each line is assumed to contain a single coordinate position consisting of
       an RA in degrees (or X in pixels) followed by a Dec in degrees (or Y in pixels). The usual
       delimiters are supported (spaces, commas, tabs). For example:

        # read from stdin, default column names and units
        [sh] funsky snr.ev
        22.982695    58.606523   # input RA (hrs), Dec(deg)
           510.00       510.00
        22.982127    58.607634   # input
           512.00       510.50
        22.981700    58.614301   # input
           513.50       513.50
        ^D                       # end of input

       If a second argument is supplied, this argument is assumed to be a file containing RA (X)
       and Dec (Y) positions. The file can either be an ASCII table or a FITS binary table. The
       order of columns is unimportant, if the table has a column header. In this case, the names
       of the columns must be one of "RA", "DEC", or "X", "Y" for sky to image and image to sky
       conversions, respectively. If the table has no header, then once again, RA (X) is assumed
       to first, followed by DEC (Y).  For example:

         # read from file, default column names and units
         [sh] cat hd.in
                RA          DEC
         ---------    ---------
         22.982695    58.606523
         22.982127    58.607634
         22.981700    58.614301

         [sh] funsky snr.ev hd.in
               510.00       510.00
               512.00       510.50
               513.50       513.50

       If three arguments are supplied, then the input positions again are read from the standard
       input. Each line is assumed to contain a single coordinate position consisting of an RA
       (or X in pixels) followed by a Dec (or Y in pixels), with the usual delimiters supported.
       However, the second and third arguments now specify the column names and/or sky units
       using a colon-delimited syntax:

         [colname]:[h⎪d⎪r]

       If the colname is omitted, the names default to "RA", "DEC", "X", "Y", "COL1", or "COL2"
       as above. If the units are omitted, the default is degrees for both RA and Dec. When the
       -r switch is used (convert from image to sky) the units are applied to the output instead
       of the input. The following examples will serve to illustrate the options:

         # read from stdin, specifying column names (def. units: degrees)
         [sh] cat hd.in
              MYRA        MYDEC
         ---------    ---------
         22.982695    58.606523
         22.982127    58.607634
         22.981700    58.614301

         [sh] funsky snr.ev MYRA MYDEC < hd.in
               510.00       510.00
               512.00       510.50
               513.50       513.50

         # read from stdin, specifying column names and units
         [sh] cat dd.in
              MYRA        MYDEC
         ---------    ---------
         344.740432    58.606523
         344.731900    58.607634
         344.725500    58.614301

         [sh] funsky snr.ev MYRA:d MYDEC:d < dd.in
               510.00       510.00
               512.00       510.50
               513.50       513.50

         # read stdin, convert image to sky, specifying output sky units
         [sh] cat im.in
               510.00       510.00
               512.00       510.50
               513.50       513.50

         [sh] cat im.in ⎪ funsky -r snr.ev :d :d
         344.740432    58.606523
         344.731900    58.607634
         344.725500    58.614301

       Finally, four command arguments specify both and input file and column names and/or units:

         [sh] cat dd.in
              MYRA        MYDEC
         ---------    ---------
         344.740432    58.606523
         344.731900    58.607634
         344.725500    58.614301

         [sh] funsky snr.ev dd.in MYRA:d MYDEC:d
               510.00       510.00
               512.00       510.50
               513.50       513.50

         # read file, convert image to sky, specifying output sky units
         [sh] cat im.in
               510.00       510.00
               512.00       510.50
               513.50       513.50

         [sh] funsky -r snr.ev im.in :d :d
           344.740432    58.606523
           344.731900    58.607634
           344.725500    58.614301

       By default, the output of funsky consists only of the converted coordinate position(s),
       one per output line. This makes parsing in shell scripts easy.  Use the -v (verbose)
       switch to specify that the input coordinates should be pre-pended to each line. For
       example:

         [sh] cat dd.in
              MYRA        MYDEC
         ---------    ---------
         344.740432    58.606523
         344.731900    58.607634
         344.725500    58.614301

         [sh] funsky snr.ev dd.in MYRA:d MYDEC:d
               510.00       510.00
               512.00       510.50
               513.50       513.50

         [sh] funsky -v snr.ev dd.in MYRA:d MYDEC:d
           344.740432    58.606523       510.00       510.00
           344.731900    58.607634       512.00       510.50
           344.725500    58.614301       513.50       513.50

       In addition, a full starbase table can be output using the -T (table) switch.  This switch
       can be used with or without the -v switch. If the -T and -v are both specified, then a
       descriptive header parameters are output before the table (mainly to remind you of the sky
       units):

         # output table in non-verbose mode
         [sh] funsky -T snr.ev dd.in MYRA:d MYDEC:d
                    X               Y
         ------------    ------------
               510.00          510.00
               512.00          510.50
               513.50          513.50

         # output table in verbose mode
         [sh] funsky -T -v snr.ev dd.in MYRA:d MYDEC:d
         # IFILE = /Users/eric/data/snr.ev
         # ICOL1 = MYRA
         # ICOL2 = MYDEC
         # IUNITS1 = d
         # IUNITS2 = d
         # OCOL1 = X
         # OCOL2 = Y

                 MYRA           MYDEC               X               Y
         ------------    ------------    ------------    ------------
           344.740432       58.606523          510.00          510.00
           344.731900       58.607634          512.00          510.50
           344.725500       58.614301          513.50          513.50

       Finally, the -d (ds9) switch mimicks ds9's use of integer TLMIN and TLMAX values for all
       coordinate transformations.  FITS conventions seem to call for use of floating point TLMIN
       and TLMAX when the data are floats. This convention is followed by funsky but results in a
       small discrepancy with ds9's converted values for floating point data. We will remedy this
       conflict in the future, maybe.

SEE ALSO

       See funtools(7) for a list of Funtools help pages