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

FreeBSD Manual Pages

  
 
  

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

NAME
       gmx-gangle - Calculate angles

SYNOPSIS
	  gmx gangle [-f [<.xtc/.trr/...>]] [-s	[<.tpr/.gro/...>]] [-n [<.ndx>]]
		     [-oav [<.xvg>]] [-oall [<.xvg>]] [-oh [<.xvg>]]
		     [-b <time>] [-e <time>] [-dt <time>] [-tu <enum>]
		     [-fgroup <selection>] [-xvg <enum>] [-[no]rmpbc]
		     [-[no]pbc]	[-sf <file>] [-selrpos <enum>]
		     [-seltype <enum>] [-g1 <enum>] [-g2 <enum>] [-binw	<real>]
		     [-group1 <selection>] [-group2 <selection>]

DESCRIPTION
       gmx gangle computes different types of angles between vectors.  It sup-
       ports  both  vectors defined by two positions and normals of planes de-
       fined by	three positions.  The z	axis or	the local normal of  a	sphere
       can also	be used	as one of the vectors.	There are also convenience op-
       tions  'angle' and 'dihedral' for calculating bond angles and dihedrals
       defined by three/four positions.

       The type	of the angle is	specified with -g1 and -g2.  If	-g1  is	 angle
       or dihedral, -g2	should not be specified.  In this case,	-group1	should
       specify	one  or	 more  selections, and each should contain triplets or
       quartets	of positions that define the angles to be calculated.

       If -g1 is vector	or plane, -group1 should specify selections that  con-
       tain  either  pairs (vector) or triplets	(plane)	of positions. For vec-
       tors, the positions set the endpoints of	the vector,  and  for  planes,
       the  three  positions are used to calculate the normal of the plane. In
       both cases, -g2 specifies the other vector to use (see below).

       With -g2	vector or -g2 plane, -group2 should  specify  another  set  of
       vectors.	 -group1  and -group2 should specify the same number of	selec-
       tions. It is also allowed to only have a	single selection  for  one  of
       the  options, in	which case the same selection is used with each	selec-
       tion in the other group.	 Similarly, for	each selection in -group1, the
       corresponding selection in -group2 should specify the  same  number  of
       vectors or a single vector. In the latter case, the angle is calculated
       between that single vector and each vector from the other selection.

       With -g2	sphnorm, each selection	in -group2 should specify a single po-
       sition  that  is	the center of the sphere.  The second vector is	calcu-
       lated as	the vector from	the center to the midpoint  of	the  positions
       specified by -group1.

       With -g2	z, -group2 is not necessary, and angles	between	the first vec-
       tors and	the positive Z axis are	calculated.

       With  -g2  t0, -group2 is not necessary,	and angles are calculated from
       the vectors as they are in the first frame.

       There are three options for output: -oav	writes an xvg  file  with  the
       time  and the average angle for each frame.  -oall writes all the indi-
       vidual angles.  -oh writes a histogram of the angles. The bin width can
       be set with -binw.  For -oav and	 -oh,  separate	 average/histogram  is
       computed	for each selection in -group1.

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:

       -oav [<.xvg>] (angaver.xvg) (Optional)
	      Average angles as	a function of time

       -oall [<.xvg>] (angles.xvg) (Optional)
	      All angles as a function of time

       -oh [<.xvg>] (anghist.xvg) (Optional)
	      Histogram	of the angles

       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

       -g1 <enum> (angle)
	      Type  of	analysis/first	vector group: angle, dihedral, vector,
	      plane

       -g2 <enum> (none)
	      Type of second vector group: none, vector, plane,	t0, z, sphnorm

       -binw <real> (1)
	      Binwidth for -oh in degrees

       -group1 <selection>
	      First analysis/vector selection

       -group2 <selection>
	      Second analysis/vector selection

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-GANGLE(1)

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

home | help