NAME¶
funmerge - merge one or more Funtools table files
SYNOPSIS¶
funmerge [\-w⎪\-x] \-f [colname] <iname1> <iname2> ...
<oname>
OPTIONS¶
-f # output a column specifying file from which this event came
-w # adjust position values using WCS info
-x # adjust position values using WCS info and save old values
DESCRIPTION¶
funmerge merges FITS data from one or more FITS Binary Table files or raw
event files.
The first argument to the program specifies the first input FITS table or raw
event file. If "stdin" is specified, data are read from the standard
input. Use Funtools Bracket Notation to specify FITS extensions and row
filters. Subsequent arguments specify additional event files and tables to
merge. (NB: Stdin cannot not be used for any of these additional input file
arguments.) The last argument is the output FITS file. The columns in each
input table must be identical.
If an input file begins with the '@' character, it is processed as an include
file, i.e., as a text file containing event file names (as well as blank lines
and/or comment lines starting with the '#' sign). If standard input is
specified as an include file ('@stdin'), then file names are read from the
standard input until EOF (^D). Event files and include files can be mixed on a
command line.
Rows from each table are written sequentially to the output file. If the switch
\-f [colname] is specified on the command line, an additional column is
added to each row containing the number of the file from which that row was
taken (starting from one). In this case, the corresponding file names are
stored in the header parameters having the prefix
FUNFIL, i.e.,
FUNFIL01, FUNFIL02, etc.
Using the
\-w switch (or
\-x switch as described below),
funmerge also can adjust the position column values using the WCS
information in each file. (By position columns, we mean the columns that the
table is binned on, i.e., those columns defined by the
bincols= switch,
or (X,Y) by default.) To perform WCS alignment, the WCS of the first file is
taken as the base WCS. Each position in subsequent files is adjusted by first
converting it to the sky coordinate in its own WCS coordinate system, then by
converting this sky position to the sky position of the base WCS, and finally
converting back to a pixel position in the base system. Note that in order to
perform WCS alignment, the appropriate WCS and TLMIN/TLMAX keywords must
already exist in each FITS file.
When performing WCS alignment, you can save the original positions in the output
file by using the
\-x (for "xtra") switch instead of the
\-w switch (i.e., using this switch also implies using
\-w) The
old positions are saved in columns having the same name as the original
positional columns, with the added prefix "OLD_".
Examples:
Merge two tables, and preserve the originating file number for each row in the
column called "FILE" (along with the corresponding file name in the
header):
[sh] funmerge -f "FILE" test.ev test2.ev merge.ev
Merge two tables with WCS alignment, saving the old position values in 2
additional columns:
[sh] funmerge -x test.ev test2.ev merge.ev
This program only works on raw event files and binary tables. We have not yet
implemented image and array merging.
SEE ALSO¶
See
funtools(7) for a list of Funtools help pages