NAME

       funcone - cone search of a binary table containing RA, Dec columns

SYNOPSIS

       funcone <switches>  <iname> <oname> <ra[hdr]> <dec[hdr]> <radius[dr'"]> [columns]

OPTIONS

         -d deccol:[hdr]  # Dec column name, units (def: DEC:d)
         -j               # join columns from list file
         -J               # join columns from list file, output all rows
         -l listfile      # read centers and radii from a list
         -L listfile      # read centers and radii from a list, output list rows
         -n               # don't use cone limits as a filter
         -r  racol:[hdr]  # RA column name, units (def: RA:h)
         -x               # append RA_CEN, DEC_CEN, RAD_CEN, CONE_KEY cols
         -X               # append RA_CEN, DEC_CEN, RAD_CEN, CONE_KEY cols, output all rows

DESCRIPTION

       Funcone  performs  a  cone search on the RA and Dec columns of a FITS binary table. The distance from the
       center RA, Dec position to the RA, Dec in each row in the table is calculated.  Rows  whose  distance  is
       less than the specified radius are output.

       The first argument to the program specifies the FITS file, raw event file, or raw array file.  If "stdin"
       is  specified,  data  are  read  from  the  standard input. Use Funtools Bracket Notation to specify FITS
       extensions, and filters.  The second argument is the output FITS file.  If  "stdout"  is  specified,  the
       FITS binary table is written to the standard output.

       The  third and fourth required arguments are the RA and Dec center position.  By default, RA is specified
       in hours while Dec is specified in degrees.  You can change the units of either of these by appending the
       character "d" (degrees), "h" (hours) or "r" (radians). Sexagesimal notation is supported, with colons  or
       spaces separating hms and dms.  (When using spaces, please ensure that the entire string is quoted.)

       The  fifth  required  argument is the radius of the cone search. By default, the radius value is given in
       degrees. The units can be changed by appending the character  "d"  (degrees),  "r"  (radians),  "'"  (arc
       minutes) or '"' (arc seconds).

       By  default, all columns of the input file are copied to the output file.  Selected columns can be output
       using an optional sixth argument in the form:

         "column1 column1 ... columnN"

       A seventh argument allows you to output selected columns from the list file when -j switch is used.  Note
       that the RA and Dec columns used in the cone calculation must not be de-selected.

       Also  by  default,  the RA and Dec column names are named "RA" and "Dec", and are given in units of hours
       and degrees respectively. You can change both the name and the units using the -r [RA]  and/or  -d  [Dec]
       switches. Once again, one of "h", "d", or "r" is appended to the column name to specify units but in this
       case, there must be a colon ":" between the name and the unit specification.

       If  the  -l  [listfile]  switch is used, then one or more of the center RA, center Dec, and radius can be
       taken from a list file (which can be a FITS table or an ASCII column text file). In this case, the  third
       (center  RA),  fourth (center Dec), and fifth (radius) command line arguments can either be a column name
       in the list file (if that parameter varies) or else a numeric value (if that parameter is static). When a
       column name is specified for the RA, Dec, or radius, you can append a colon followed by "h", "d", or  "r"
       to  specify  units  (also  ' and " for radius). The cone search algorithm is run once for each row in the
       list, taking RA, Dec, and radius values  from  the  specified  columns  or  from  static  numeric  values
       specified on the command line.

       When  using  a  list, all valid rows from each iteration are written to a single output file.  Use the -x
       switch to help delineate which line of the list file was used to produce the given output  row(s).   This
       switch  causes  the  values  for  the center RA, Dec, radius, and row number to be appended to the output
       file, in columns called RA_CEN, DEC_CEN, RAD_CEN and CONE_KEY, respectively. Alternatively, the -j (join)
       switch will append all columns from the list row to the output row (essentially a join of  the  list  row
       and input row), along with the CONE_KEY row number. These two switches are mutually exclusive.

       The -X and -J switches write out the same data as their lower case counterparts for each row satisfying a
       cone  search. In addition, these switches also write out rows from the event file that do not satisfy any
       cone search.  In such cases, that CONE_KEY column will be given a value of -1 and  the  center  and  list
       position  information  will  be set to zero for the given row. Thus, all rows of the input event file are
       guaranteed to be output, with  rows  satisfying  at  least  one  cone  search  having  additional  search
       information.

       The -L switch acts similarly to the -l switch in that it takes centers from a list file. However, it also
       implicitly  sets  the  -j  switch, so that output rows are the join of the input event row and the center
       position row.  In addition, this switch also writes out all center  position  rows  for  which  no  event
       satisfies  the  cone  search  criteria  of that row.  The CONE_KEY column will be given a value of -2 for
       center rows that were not close to any data row and the event columns will be zeroed out for  such  rows.
       In this way, all centers rows are guaranteed to be output at least once.

       If any of "all row" switches (-X, -J, or -L) are specified, then a new column named JSTAT is added to the
       output  table.  The positive values in this column indicate the center position row number (starting from
       1) in the list file that this data row successful matched in a cone search. A value of -1 means that  the
       data  row did not match any center position. A value of -2 means that the center position was not matched
       by any data row.

       Given a center position and radius, the cone search algorithm  calculates  limit  parameters  for  a  box
       enclosing  the  specified  cone, and only tests rows whose positions values lie within those limits.  For
       small files, the overhead associated with this cone limit filtering can cause the  program  to  run  more
       slowly  than  if all events were tested. You can turn off cone limit filtering using the -n switch to see
       if this speeds up the processing (especially useful when processing a large list of positions).

       For example, the default cone search uses columns "RA" and "Dec" in hours and degrees (respectively)  and
       RA position in hours, Dec and radius in degrees:

         funone in.fits out.fits 23.45 34.56 0.01

       To specify the RA position in degrees:

         funcone in.fits out.fits 23.45d 34.56 0.01

       To get RA and Dec from a list but use a static value for radius (and also write identifying info for each
       row in the list):

         funcone -x -l list.txt in.fits out.fits MYRA MYDec 0.01

       User  specified  columns in degrees, RA position in hours (sexagesimal notation), Dec position in degrees
       (sexagesimal notation) and radius in arc minutes:

         funcone -r myRa:d -d myDec in.fits out.fits 12:30:15.5 30:12 15'

SEE ALSO

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

version 1.4.5                                    April 14, 2011                                       funcone(1)