1 .TH g_angle 1 "Thu 16 Oct 2008"
3 g_angle - calculates distributions and correlations for angles and dihedrals
10 .BI "-od" " angdist.xvg "
11 .BI "-ov" " angaver.xvg "
12 .BI "-of" " dihfrac.xvg "
13 .BI "-ot" " dihtrans.xvg "
14 .BI "-oh" " trhisto.xvg "
15 .BI "-oc" " dihcorr.xvg "
16 .BI "-or" " traj.trr "
26 .BI "-binwidth" " real "
27 .BI "-[no]periodic" ""
28 .BI "-[no]chandler" ""
29 .BI "-[no]avercorr" ""
31 .BI "-[no]normalize" ""
35 .BI "-beginfit" " real "
36 .BI "-endfit" " real "
38 g_angle computes the angle distribution for a number of angles
39 or dihedrals. This way you can check whether your simulation
40 is correct. With option -ov you can plot the average angle of
41 a group of angles as a function of time. With the -all option
42 the first graph is the average, the rest are the individual angles.
45 With the -of option g_angle also calculates the fraction of trans
46 dihedrals (only for dihedrals) as function of time, but this is
47 probably only fun for a selected few.
50 With option -oc a dihedral correlation function is calculated.
53 It should be noted that the indexfile should contain
54 atom-triples for angles or atom-quadruplets for dihedrals.
55 If this is not the case, the program will crash.
60 a trajectory file is dumped containing cos andsin of selected dihedral angles which subsequently can be used as
61 input for a PCA analysis using
67 Trajectory: xtc trr trj gro g96 pdb cpt
73 .BI "-od" " angdist.xvg"
77 .BI "-ov" " angaver.xvg"
81 .BI "-of" " dihfrac.xvg"
85 .BI "-ot" " dihtrans.xvg"
89 .BI "-oh" " trhisto.xvg"
93 .BI "-oc" " dihcorr.xvg"
99 Trajectory in portable xdr format
103 Print help info and quit
105 .BI "-nice" " int" " 19"
108 .BI "-b" " time" " 0 "
109 First frame (ps) to read from trajectory
111 .BI "-e" " time" " 0 "
112 Last frame (ps) to read from trajectory
114 .BI "-dt" " time" " 0 "
115 Only use frame when t MOD dt = first time (ps)
118 View output xvg, xpm, eps and pdb files
120 .BI "-[no]xvgr" "yes "
121 Add specific codes (legends etc.) in the output xvg files for the xmgrace program
123 .BI "-type" " enum" " angle"
124 Type of angle to analyse:
131 .B ryckaert-bellemans
135 Plot all angles separately in the averages file, in the order of appearance in the index file.
137 .BI "-binwidth" " real" " 1 "
138 binwidth (degrees) for calculating the distribution
140 .BI "-[no]periodic" "yes "
141 Print dihedral angles modulo 360 degrees
143 .BI "-[no]chandler" "no "
144 Use Chandler correlation function (N[trans] = 1, N[gauche] = 0) rather than cosine correlation function. Trans is defined as phi -60 || phi 60.
146 .BI "-[no]avercorr" "no "
147 Average the correlation functions for the individual angles/dihedrals
149 .BI "-acflen" " int" " -1"
150 Length of the ACF, default is half the number of frames
152 .BI "-[no]normalize" "yes "
155 .BI "-P" " enum" " 0"
156 Order of Legendre polynomial for ACF (0 indicates none):
166 .BI "-fitfn" " enum" " none"
185 .BI "-ncskip" " int" " 0"
186 Skip N points in the output file of correlation functions
188 .BI "-beginfit" " real" " 0 "
189 Time where to begin the exponential fit of the correlation function
191 .BI "-endfit" " real" " -1 "
192 Time where to end the exponential fit of the correlation function, -1 is till the end
195 \- Counting transitions only works for dihedrals with multiplicity 3