Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
GMX-SELECT(1)			    GROMACS			 GMX-SELECT(1)

NAME
       gmx-select - Print general information about selections

SYNOPSIS
	  gmx select [-f [<.xtc/.trr/...>]] [-s	[<.tpr/.gro/...>]] [-n [<.ndx>]]
		     [-os [<.xvg>]] [-oc [<.xvg>]] [-oi	[<.dat>]]
		     [-on [<.ndx>]] [-om [<.xvg>]] [-of	[<.xvg>]]
		     [-ofpdb [<.pdb>]] [-olt [<.xvg>]] [-b <time>] [-e <time>]
		     [-dt <time>] [-tu <enum>] [-fgroup	<selection>]
		     [-xvg <enum>] [-[no]rmpbc]	[-[no]pbc] [-sf	<file>]
		     [-selrpos <enum>] [-seltype <enum>] [-select <selection>]
		     [-[no]norm] [-[no]cfnorm] [-resnr <enum>]
		     [-pdbatoms	<enum>]	[-[no]cumlt]

DESCRIPTION
       gmx  select  writes out basic data about	dynamic	selections.  It	can be
       used for	some simple analyses, or the output can	be combined with  out-
       put  from other programs	and/or external	analysis programs to calculate
       more complex things.  For detailed help on the selection	syntax,	please
       use gmx help selections.

       Any combination of the output options is	possible, but  note  that  -om
       only operates on	the first selection.  Also note	that if	you provide no
       output options, no output is produced.

       With -os, calculates the	number of positions in each selection for each
       frame.  With  -norm,  the  output  is between 0 and 1 and describes the
       fraction	from the maximum number	 of  positions	(e.g.,	for  selection
       'resname	RA and x < 5' the maximum number of positions is the number of
       atoms in	RA residues). With -cfnorm, the	output is divided by the frac-
       tion  covered by	the selection.	-norm and -cfnorm can be specified in-
       dependently of one another.

       With -oc, the fraction covered by each selection	is written  out	 as  a
       function	of time.

       With  -oi,  the	selected atoms/residues/molecules are written out as a
       function	of time. In the	output,	the first column  contains  the	 frame
       time,  the  second  contains  the  number of positions, followed	by the
       atom/residue/molecule numbers.  If more than one	 selection  is	speci-
       fied,  the size of the second group immediately follows the last	number
       of the first group and so on.

       With -on, the selected atoms are	written	as  a  index  file  compatible
       with  make_ndx  and the analyzing tools.	Each selection is written as a
       selection group and for dynamic selections a group is written for  each
       frame.

       For  residue  numbers, the output of -oi	can be controlled with -resnr:
       number (default)	prints the residue numbers as they appear in the input
       file, while index prints	unique numbers assigned	to the residues	in the
       order they appear in the	input file, starting with  1.  The  former  is
       more  intuitive,	 but  if the input contains multiple residues with the
       same number, the	output can be less useful.

       With -om, a mask	is printed for the first selection as  a  function  of
       time.  Each  line  in the output	corresponds to one frame, and contains
       either 0/1 for each atom/residue/molecule possibly selected.  1	stands
       for  the	 atom/residue/molecule being selected for the current frame, 0
       for not selected.

       With -of, the occupancy fraction	of each	position (i.e.,	 the  fraction
       of frames where the position is selected) is printed.

       With  -ofpdb,  a	 PDB file is written out where the occupancy column is
       filled with the occupancy fraction of each atom in the  selection.  The
       coordinates  in	the  PDB  file	will be	those from the input topology.
       -pdbatoms can be	used to	control	which atoms appear in the  output  PDB
       file:  with  all	 all atoms are present,	with maxsel all	atoms possibly
       selected	by the selection are present, and  with	 selected  only	 atoms
       that are	selected at least in one frame are present.

       With  -olt,  a  histogram is produced that shows	the number of selected
       positions as a function of the time the position	was  continuously  se-
       lected.	-cumlt	can  be	used to	control	whether	subintervals of	longer
       intervals are included in the histogram.

       -om, -of, and -olt only make sense with dynamic selections.

       To plot coordinates for selections, use gmx trajectory.

OPTIONS
       Options to specify input	files:

       -f [<.xtc/.trr/...>] (traj.xtc) (Optional)
	      Input trajectory or single configuration:	xtc trr	 cpt  gro  g96
	      pdb tng

       -s [<.tpr/.gro/...>] (topol.tpr)	(Optional)
	      Input structure: tpr gro g96 pdb brk ent

       -n [<.ndx>] (index.ndx) (Optional)
	      Extra index groups

       Options to specify output files:

       -os [<.xvg>] (size.xvg) (Optional)
	      Number of	positions in each selection

       -oc [<.xvg>] (cfrac.xvg)	(Optional)
	      Covered fraction for each	selection

       -oi [<.dat>] (index.dat)	(Optional)
	      Indices selected by each selection

       -on [<.ndx>] (index.ndx)	(Optional)
	      Index file from the selection

       -om [<.xvg>] (mask.xvg) (Optional)
	      Mask for selected	positions

       -of [<.xvg>] (occupancy.xvg) (Optional)
	      Occupied fraction	for selected positions

       -ofpdb [<.pdb>] (occupancy.pdb) (Optional)
	      PDB file with occupied fraction for selected positions

       -olt [<.xvg>] (lifetime.xvg) (Optional)
	      Lifetime histogram

       Other options:

       -b <time> (0)
	      First frame (ps) to read from trajectory

       -e <time> (0)
	      Last frame (ps) to read from trajectory

       -dt <time> (0)
	      Only use frame if	t MOD dt == first time (ps)

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

       -fgroup <selection>
	      Atoms  stored in the trajectory file (if not set,	assume first N
	      atoms)

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

       -[no]rmpbc (yes)
	      Make molecules whole for each frame

       -[no]pbc	(yes)
	      Use periodic boundary conditions for distance calculation

       -sf <file>
	      Provide selections from files

       -selrpos	<enum> (atom)
	      Selection	reference positions: atom, res_com, res_cog,  mol_com,
	      mol_cog,	   whole_res_com,     whole_res_cog,	whole_mol_com,
	      whole_mol_cog,   part_res_com,	part_res_cog,	 part_mol_com,
	      part_mol_cog, dyn_res_com, dyn_res_cog, dyn_mol_com, dyn_mol_cog

       -seltype	<enum> (atom)
	      Default  selection  output  positions:  atom,  res_com, res_cog,
	      mol_com, mol_cog,	whole_res_com,	whole_res_cog,	whole_mol_com,
	      whole_mol_cog,	part_res_com,	 part_res_cog,	 part_mol_com,
	      part_mol_cog, dyn_res_com, dyn_res_cog, dyn_mol_com, dyn_mol_cog

       -select <selection>
	      Selections to analyze

       -[no]norm (no)
	      Normalize	by total number	of positions with -os

       -[no]cfnorm (no)
	      Normalize	by covered fraction with -os

       -resnr <enum> (number)
	      Residue number output type with -oi and -on: number, index

       -pdbatoms <enum>	(all)
	      Atoms to write with -ofpdb: all, maxsel, selected

       -[no]cumlt (yes)
	      Cumulate subintervals of longer intervals	in -olt

SEE ALSO
       gmx(1)

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

COPYRIGHT
       2025, GROMACS development team

2025.0				 Feb 10, 2025			 GMX-SELECT(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=gmx-select&sektion=1&manpath=FreeBSD+Ports+14.3.quarterly>

home | help