NAME

       g_gyrate - calculates the radius of gyration

       VERSION 4.6.5

SYNOPSIS

       g_gyrate  -f  traj.xtc  -s  topol.tpr  -n  index.ndx -o gyrate.xvg -acf moi-acf.xvg -[no]h
       -[no]version -nice int -b time -e time -dt time -[no]w -xvg enum -nmol int  -[no]q  -[no]p
       -[no]moi -nz int -acflen int -[no]normalize -P enum -fitfn enum -ncskip int -beginfit real
       -endfit real

DESCRIPTION

        g_gyrate computes the radius of gyration of a molecule and the radii  of  gyration  about
       the  x-,  y- and  z-axes, as a function of time. The atoms are explicitly mass weighted.

       With the  -nmol option the radius of gyration will be calculated for multiple molecules by
       splitting the analysis group in equally sized parts.

       With the option  -nz 2D radii of gyration in the  x-y plane of slices  along  the   z-axis
       are calculated.

FILES

       -f traj.xtc Input
        Trajectory: xtc trr trj gro g96 pdb cpt

       -s topol.tpr Input
        Structure+mass(db): tpr tpb tpa gro g96 pdb

       -n index.ndx Input, Opt.
        Index file

       -o gyrate.xvg Output
        xvgr/xmgr file

       -acf moi-acf.xvg Output, Opt.
        xvgr/xmgr file

OTHER OPTIONS

       -[no]hno
        Print help info and quit

       -[no]versionno
        Print version info and quit

       -nice int 19
        Set the nicelevel

       -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 when t MOD dt = first time (ps)

       -[no]wno
        View output  .xvg,  .xpm,  .eps and  .pdb files

       -xvg enum xmgrace
        xvg plot formatting:  xmgrace,  xmgr or  none

       -nmol int 1
        The number of molecules to analyze

       -[no]qno
        Use absolute value of the charge of an atom as weighting factor instead of mass

       -[no]pno
        Calculate the radii of gyration about the principal axes.

       -[no]moino
        Calculate the moments of inertia (defined by the principal axes).

       -nz int 0
        Calculate the 2D radii of gyration of this number of slices along the z-axis

       -acflen int -1
        Length of the ACF, default is half the number of frames

       -[no]normalizeyes
        Normalize ACF

       -P enum 0
        Order of Legendre polynomial for ACF (0 indicates none):  0,  1,  2 or  3

       -fitfn enum none
        Fit function:  none,  exp,  aexp,  exp_exp,  vac,  exp5,  exp7,  exp9 or  erffit

       -ncskip int 0
        Skip this many points in the output file of correlation functions

       -beginfit real 0
        Time where to begin the exponential fit of the correlation function

       -endfit real -1
        Time where to end the exponential fit of the correlation function, -1 is until the end

SEE ALSO

       gromacs(7)

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

                                          Mon 2 Dec 2013                              g_gyrate(1)