def calc_bondacf(args):
"""
calculates persitence length using bond correlation function
bondacf: bond correlation function analysis for L_p, when this
parameter is provided, then program analyzes first points
and fits them, to understand persistance length.
C(n) = <u_0 u_n >
method: create an array C,
loop trajectory:
loop residues:
loop bonds:
analyze angle between first bond vector and i
average results
plot using save_plots
"""
psffile = get_path_names.get_filename(args.psffile)
u = MDAnalysis.Universe(psffile + '.psf', args.traj)
Nbonds = len(u.residues[0]) - 1
Nres = len(u.residues)
print "Nres = %r" % Nres
print "Nbonds = %r" % Nbonds
bonds = np.array((Nbonds, 3))
C = np.zeros(Nbonds)
k = 0
for ts in u.trajectory[args.startframe:args.endframe:args.trajskip]:
print "time = %r" % ts.frame
for res in u.residues:
bonds = AnalyzeChain.get_bondlist_coords(res)
k += 1
for ui in range(0, Nbonds):
C[ui] += np.dot(bonds[0], bonds[ui])
C /= float(k)
ui_array = np.arange(Nbonds)
save_plots.save_plot(ui_array, C, plotname='bondacf')
def get_seg_cryst(i, bonds, threshold=0.7, neigh=4):
nleft, nright = int(neigh) / 2, int(neigh) / 2
cos2_local = 0.
AlignVec = AnalyzeChain.moving_average(bonds, neigh)
cos2_local = np.dot(AlignVec[i - nleft, :], bonds[i, :])
# cos2_local += np.dot(AlignVec[i+nright, :], bonds[i, :])
# cos2_local /= 2.
P2 = (3. * cos2_local**2.0 - 1.) / 2.
return P2
def analyze_chain_hist(u, args):
"""
loops through residues, finds crystallinity of each chain, and writes
an array of chainlengths and chaing2s(chain crystallinities)
input: Universe (MDAnalysis)
output: chainlengths, chaing2s
part of that_calculates_everything
"""
chainlengths, chaing2s = [], []
for res in u.residues:
chords = AnalyzeChain.get_bondlist_coords(res)
resid_cryst = AnalyzeChain.get_chain_crystallinity(chords)
# all_g2 += resid_cryst
chainlengths.append(len(res))
chaing2s.append(resid_cryst)
chainlengths = np.array(chainlengths)
chaing2s = np.array(chaing2s)
return chainlengths, chaing2s
def main(args):
"""main func"""
psffile = get_path_names.get_filename(args.psffile)
u = MDAnalysis.Universe(psffile + '.psf', args.traj)
bonds = AnalyzeChain.get_bondlist_coords(u.residues[0])
L = 0. # number of lamellae
# the skip on the left and on the right,
nleft, nright = int(args.neigh) / 2, int(args.neigh) / 2
Nbonds = len(bonds)
Nres = len(u.residues)
timeframes, L_array = [], []
if args.filedumpskip:
dumpskip = AnalyzeLog.get_dumpskip(filename='dumpskip.txt',
keyparameter="dump" +
args.keyparameter + "skip")
timestep = AnalyzeLog.get_timestep(filename='dumpskip.txt',
keyparameter="time" +
args.keyparameter + "step")
else:
print "using given parameters"
dumpskip = args.dumpskip
timestep = args.timestep
for ts in u.trajectory[args.startframe:args.endframe:args.trajskip]:
print "frame = {frame}, percent of lamellae={num_of_lam}"\
.format(frame=ts.frame,
num_of_lam=L/float(Nres))
timeframes.append(ts.frame)
L = 0.
for myres in u.residues:
bonds = AnalyzeChain.get_bondlist_coords(myres)
Flag = True # assume we hit the straight segment of the chain
atom_indices = [] # indices of atoms in the current lamellae
for i in xrange(nleft, Nbonds - nright - 1):
if not Flag: # if we ended a straight segment, check the len
Nlam = len(atom_indices)
if Nlam > 9:
L += 1.
# print colored( 'lamellae size is %d ' % Nlam, 'green')
# start looking for a new lamellae
atom_indices = []
Flag = True
else:
# if we still are hitting straight segments
ci = get_seg_cryst(i,
bonds,
threshold=args.threshold,
neigh=args.neigh)
if ci > args.threshold:
# print "segment = %d, | ci = %4.3f" % (i,ci)
Flag = True
atom_indices.append(i)
elif ci > 0.0:
# print "segment = %d, > ci = %4.3f" % (i,ci)
Flag = False
else:
ValueError("crystallinity is negative")
L_array.append(L / float(Nres))
timeframes = np.array(timeframes)
L_array = np.array(L_array)
save_plots.save_plot(timeframes,
L_array,
plotname='lamellae',
name=psffile,
logplot=args.logplot,
dumpskip=dumpskip,
timestep=timestep,
ylabel='frac{N_{stems}}{N_{chains}}')
def main():
args = read_parameters.read_traj_vmd()
print args
u = MDAnalysis.Universe(args.psffile, args.traj)
psffile = get_path_names.get_filename(u.filename)
n_atoms_per_box = args.nAtomsPerBox
Natoms = u.trajectory.numatoms
Nx_atoms = Natoms**(1./3.) # how many atoms in a line
Nsub = int(Nx_atoms / float(n_atoms_per_box)) # how many segements of 3 atoms
cryst_all = 0.0
# box = u.trajectory.ts.dimensions[:-3]
# length_x = box[-1]
u.SYSTEM.packIntoBox()
a = u.selectAtoms("all")
c = a.coordinates()
print c
length_x = a.bbox().max()
grid_1d = np.linspace(0.0, length_x, Nsub+1, endpoint=True)
delta = grid_1d[1] - grid_1d[0]
frame = []
g2 = []
if args.filedumpskip:
dumpskip = AnalyzeLog.get_dumpskip(filename='dumpskip.txt',
keyparameter="dump" +
args.keyparameter+"skip")
# dumpskip = args.dumpskip
timestep = AnalyzeLog.get_timestep(filename='dumpskip.txt',
keyparameter="time" +
args.keyparameter
+ "step")
else:
print "using given parameters"
dumpskip = args.dumpskip
timestep = args.timestep
# decide the skipping information
if args.auto_traj_skip:
trajskip = int(u.trajectory.numframes/120.)
if trajskip < 1:
trajskip = 1
elif args.auto_traj_skip:
trajskip = args.trajskip
else:
raise ValueError("trajskip needs to be provided")
for ts in u.trajectory[args.startframe:args.endframe:trajskip]:
# ar_z is a planar selection
u.SYSTEM.packIntoBox()
for i, z in enumerate(grid_1d[0:-1]):
ar_z = u.selectAtoms("prop z >= "
+ str(z) +
" and prop z < "
+ str(z+delta))
# print " I am in z ", z
# print len(ar_z)
# ater this step ar_y is a line
for j, y in enumerate(grid_1d[0:-1]):
ar_y = ar_z.selectAtoms("prop y >= "
+ str(y) +
" and prop y < "
+ str(y+delta))
# print " I am in y ", y
# print len(ar_y)
# ater this step ar_x is a dot
for k, x in enumerate(grid_1d[0:-1]):
ar_x = ar_y.selectAtoms("prop x >= "
+ str(x)
+ " and prop x < "
+ str(x+delta))
# print " I am in x ", x
# print len(ar_x)
bonds = AnalyzeChain.get_bondlist_coords(ar_x)
cryst_all += get_cryst(bonds, get_eigvec(bonds),
threshold=args.threshold)
frame.append(ts.frame)
cryst_all /= float(Nsub**3.0)
g2.append(cryst_all)
print "frame ", ts.frame, " cryst = ", cryst_all
frame = np.array(frame)
g2 = np.array(g2)
# os.system("convert -delay ")
save_plots.save_plot(frame, g2,
plotname='YC',
name=psffile,
logplot=args.logplot,
dumpskip=dumpskip,
timestep=timestep)
return None