.help txsort Aug91 noao.digiphot.ptools
.ih
NAME
txsort -- sort a list of APPHOT/DAOPHOT text database file(s)
.ih
USAGE
txsort textfile field
.ih
PARAMETERS
.ls textfiles 
The input APPHOT/DAOPHOT text database(s) to be sorted.
The sort is performed in place.
.le
.ls field
The field to be sorted on. \fIField\fR may be any quantity defined by
the APPHOT/DAOPHOT #K and #N keywords. The keywords may be
of type integer or real, in which case a numeric sort is performed,
boolean, in which case the boolean constant "no" has a smaller value
than "yes", or character in which case an alphabetic sort is performed.
.le
.ls ascend = yes
Sort in increasing value order.
.le
.ih
DESCRIPTION
TXSORT is a simple task which accepts a list of APPHOT/DAOPHOT text
database files
and sorts them in place based on the value of the selected field
specifier \fIfield\fR. By default the sort is performed in increasing order
of the value
of \fIfield\fR, but a reverse sort can be performed by 
setting \fIascend\fR = "no".

If \fIfield\fR is a real or integer quantity the sort is numeric; if boolean
the boolean constant "no" is assumed to have a smaller value than "yes"; if
character the sort is alphabetic.
.ih
EXAMPLES

1.  Sort the output of the APPHOT task PHOT in increasing order of
the y position.

.nf
    pt> txsort m92.mag.1 YCENTER
.fi

2. Sort the output of the DAOPHOT task ALLSTAR in increasing order of
   magnitude.

.nf
    pt> txsort m92.al.1 MAG
.fi

.ih
TIME REQUIREMENTS
.ih
BUGS
.ih
SEE ALSO
ptools.tbsort,tables.tsort,ptools.psort,sort
.endhelp