grpselect ingroupfile outgroupfile min_group max_group
ingroupfile
The list of input files. Ingroupfile must have been written
by the DAOPHOT PSF, GROUP, or NSTAR tasks.
Ingroupfile may be an APPHOT/DAOPHOT text database or an STSDAS table.
outgroupfile
The list of output files. Outgroupfile will have the
same file type as ingroupfile.
min_group
The minimum group size to select from the input file(s).
max_group
The maximum group size to select from the input file(s).
verbose = )_.verbose
Print messages about the progress of the task? Verbose may be set
to the value of the daophot package parameter (the default), "yes", or
"no".
GRPSELECT creates a new GROUP file outgroupfile by selecting groups from the input GROUP file ingroupfile within a range of group sizes specified by min_group and max_group. If ingroupfile is a DAOPHOT text database, outgroupfile is a text database. Conversely if ingroupfile is a DAOPHOT STSDAS table database, outgroupfile is an STSDAS table database.
A typical use for GRPSELECT would be to create a new database containing only groups which are less than the value of the maxgroup parameter in the DAOPARS task for direct input into the NSTAR task. The remaining stars in the larger groups are reduced by running GRPSELECT once more, selecting only groups greater than maxgroup, rerunning GROUP on the output with a less stringent value of the DAOPARS parameter task critovlap to reduce the group sizes and inputting the result into NSTAR.
1. Select groups with between 1 and 70 stars from the GROUP task output file n4147.grp.1 and write them into a new file named n4147small.grp.
da> grpselect n4147.grp.1 n4147small.grp 1 70
2. Select groups larger than 70 from the same input group table and rerun group with a larger value of critoverlap.
da> grpselect n4147.grp.1 n4147large.grp 71 400
da> group n4147 n4147large.grp n4147.psf.1 n4147.grp.2 crit=5.0
This example would create a new group table which contains the regrouped stars from the table n4147large.grp.