NAME

       gmx-trjcat - Concatenate trajectory files

SYNOPSIS

          gmx trjcat [-f [<.xtc/.trr/...> [...]]] [-n [<.ndx>]] [-demux [<.xvg>]]
                     [-o [<.xtc/.trr/...> [...]]] [-tu <enum>] [-xvg <enum>]
                     [-b <time>] [-e <time>] [-dt <time>] [-[no]settime]
                     [-[no]sort] [-[no]keeplast] [-[no]overwrite] [-[no]cat]

DESCRIPTION

       gmx trjcat concatenates several input trajectory files in sorted order.  In case of double
       time frames the one in the later file is used.  By specifying -settime you will  be  asked
       for  the  start  time  of each file. The input files are taken from the command line, such
       that a command like gmx trjcat -f *.trr -o fixed.trr should do the trick. Using -cat,  you
       can  simply  paste  several  files  together without removal of frames with identical time
       stamps.

       One important option is inferred when the output file is amongst the input files. In  that
       case  that  particular  file  will  be  appended to which implies you do not need to store
       double the amount of data.  Obviously the file to append to has to be the one with  lowest
       starting time since one can only append at the end of a file.

       If  the  -demux  option is given, the N trajectories that are read, are written in another
       order as specified in the .xvg file.  The .xvg file should contain something like:

          0  0  1  2  3  4  5
          2  1  0  2  3  5  4

       The first number is the time, and subsequent numbers point  to  trajectory  indices.   The
       frames  corresponding  to  the  numbers  present  at the first line are collected into the
       output trajectory. If the number of frames in the trajectory does not match  that  in  the
       .xvg file then the program tries to be smart. Beware.

OPTIONS

       Options to specify input files:

       -f [<.xtc/.trr/...> [...]] (traj.xtc)
              Trajectory: xtc trr cpt gro g96 pdb tng

       -n [<.ndx>] (index.ndx) (Optional)
              Index file

       -demux [<.xvg>] (remd.xvg) (Optional)
              xvgr/xmgr file

       Options to specify output files:

       -o [<.xtc/.trr/...> [...]] (trajout.xtc)
              Trajectory: xtc trr gro g96 pdb tng

       Other options:

       -tu <enum> (ps)
              Unit for time values: fs, ps, ns, us, ms, s

       -xvg <enum> (xmgrace)
              xvg plot formatting: xmgrace, xmgr, none

       -b <time> (-1)
              First time to use (ps)

       -e <time> (-1)
              Last time to use (ps)

       -dt <time> (0)
              Only write frame when t MOD dt = first time (ps)

       -[no]settime (no)
              Change starting time interactively

       -[no]sort (yes)
              Sort trajectory files (not frames)

       -[no]keeplast (no)
              Keep overlapping frames at end of trajectory

       -[no]overwrite (no)
              Overwrite overlapping frames during appending

       -[no]cat (no)
              Do not discard double time frames

SEE ALSO

       gmx(1)

       More information about GROMACS is available at <http://www.gromacs.org/>.

COPYRIGHT

       2021, GROMACS development team