1 .TH g_select 1 "Fri 19 Apr 2013" "" "GROMACS suite, VERSION 4.5.7"
3 g_select - selects groups of atoms based on flexible textual selections
9 .BI "\-s" " topol.tpr "
10 .BI "\-sf" " selection.dat "
11 .BI "\-n" " index.ndx "
12 .BI "\-os" " size.xvg "
13 .BI "\-oc" " cfrac.xvg "
14 .BI "\-oi" " index.dat "
15 .BI "\-om" " mask.dat "
16 .BI "\-on" " index.ndx "
18 .BI "\-[no]version" ""
26 .BI "\-select" " string "
27 .BI "\-selrpos" " enum "
28 .BI "\-seltype" " enum "
32 .BI "\-resnr" " enum "
34 \&\fB g_select\fR writes out basic data about dynamic selections.
35 \&It can be used for some simple analyses, or the output can
36 \&be combined with output from other programs and/or external
37 \&analysis programs to calculate more complex things.
38 \&Any combination of the output options is possible, but note
39 \&that \fB \-om\fR only operates on the first selection.
40 \&\fB \-os\fR is the default output option if none is selected.
43 \&With \fB \-os\fR, calculates the number of positions in each
44 \&selection for each frame. With \fB \-norm\fR, the output is
45 \&between 0 and 1 and describes the fraction from the maximum
46 \&number of positions (e.g., for selection 'resname RA and x 5'
47 \&the maximum number of positions is the number of atoms in
48 \&RA residues). With \fB \-cfnorm\fR, the output is divided
49 \&by the fraction covered by the selection.
50 \&\fB \-norm\fR and \fB \-cfnorm\fR can be specified independently
54 \&With \fB \-oc\fR, the fraction covered by each selection is
55 \&written out as a function of time.
58 \&With \fB \-oi\fR, the selected atoms/residues/molecules are
59 \&written out as a function of time. In the output, the first
60 \&column contains the frame time, the second contains the number
61 \&of positions, followed by the atom/residue/molecule numbers.
62 \&If more than one selection is specified, the size of the second
63 \&group immediately follows the last number of the first group
64 \&and so on. With \fB \-dump\fR, the frame time and the number
65 \&of positions is omitted from the output. In this case, only one
66 \&selection can be given.
69 \&With \fB \-on\fR, the selected atoms are written as a index file
70 \&compatible with \fB make_ndx\fR and the analyzing tools. Each selection
71 \&is written as a selection group and for dynamic selections a
72 \&group is written for each frame.
75 \&For residue numbers, the output of \fB \-oi\fR can be controlled
76 \&with \fB \-resnr\fR: \fB number\fR (default) prints the residue
77 \&numbers as they appear in the input file, while \fB index\fR prints
78 \&unique numbers assigned to the residues in the order they appear
79 \&in the input file, starting with 1. The former is more intuitive,
80 \&but if the input contains multiple residues with the same number,
81 \&the output can be less useful.
84 \&With \fB \-om\fR, a mask is printed for the first selection
85 \&as a function of time. Each line in the output corresponds to
86 \&one frame, and contains either 0/1 for each atom/residue/molecule
87 \&possibly selected. 1 stands for the atom/residue/molecule being
88 \&selected for the current frame, 0 for not selected.
89 \&With \fB \-dump\fR, the frame time is omitted from the output.
93 Trajectory: xtc trr trj gro g96 pdb cpt
95 .BI "\-s" " topol.tpr"
97 Structure+mass(db): tpr tpb tpa gro g96 pdb
99 .BI "\-sf" " selection.dat"
103 .BI "\-n" " index.ndx"
107 .BI "\-os" " size.xvg"
111 .BI "\-oc" " cfrac.xvg"
115 .BI "\-oi" " index.dat"
119 .BI "\-om" " mask.dat"
123 .BI "\-on" " index.ndx"
129 Print help info and quit
131 .BI "\-[no]version" "no "
132 Print version info and quit
134 .BI "\-nice" " int" " 19"
137 .BI "\-b" " time" " 0 "
138 First frame (ps) to read from trajectory
140 .BI "\-e" " time" " 0 "
141 Last frame (ps) to read from trajectory
143 .BI "\-dt" " time" " 0 "
144 Only use frame when t MOD dt = first time (ps)
146 .BI "\-xvg" " enum" " xmgrace"
147 xvg plot formatting: \fB xmgrace\fR, \fB xmgr\fR or \fB none\fR
149 .BI "\-[no]rmpbc" "yes "
150 Make molecules whole for each frame
152 .BI "\-[no]pbc" "yes "
153 Use periodic boundary conditions for distance calculation
155 .BI "\-select" " string" " "
156 Selection string (use 'help' for help). Note that the whole selection string will need to be quoted so that your shell will pass it in as a string. Example: \fB g_select \-select '"Nearby water" resname SOL and within 0.25 of group Protein'\fR
158 .BI "\-selrpos" " enum" " atom"
159 Selection reference position: \fB atom\fR, \fB res_com\fR, \fB res_cog\fR, \fB mol_com\fR, \fB mol_cog\fR, \fB whole_res_com\fR, \fB whole_res_cog\fR, \fB whole_mol_com\fR, \fB whole_mol_cog\fR, \fB part_res_com\fR, \fB part_res_cog\fR, \fB part_mol_com\fR, \fB part_mol_cog\fR, \fB dyn_res_com\fR, \fB dyn_res_cog\fR, \fB dyn_mol_com\fR or \fB dyn_mol_cog\fR
161 .BI "\-seltype" " enum" " atom"
162 Default analysis positions: \fB atom\fR, \fB res_com\fR, \fB res_cog\fR, \fB mol_com\fR, \fB mol_cog\fR, \fB whole_res_com\fR, \fB whole_res_cog\fR, \fB whole_mol_com\fR, \fB whole_mol_cog\fR, \fB part_res_com\fR, \fB part_res_cog\fR, \fB part_mol_com\fR, \fB part_mol_cog\fR, \fB dyn_res_com\fR, \fB dyn_res_cog\fR, \fB dyn_mol_com\fR or \fB dyn_mol_cog\fR
164 .BI "\-[no]dump" "no "
165 Do not print the frame time (\-om, \-oi) or the index size (\-oi)
167 .BI "\-[no]norm" "no "
168 Normalize by total number of positions with \-os
170 .BI "\-[no]cfnorm" "no "
171 Normalize by covered fraction with \-os
173 .BI "\-resnr" " enum" " number"
174 Residue number output type: \fB number\fR or \fB index\fR
179 More information about \fBGROMACS\fR is available at <\fIhttp://www.gromacs.org/\fR>.