Source code for MDAnalysis.topology.tpr.utils

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# MDAnalysis --- https://www.mdanalysis.org
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# (see the file AUTHORS for the full list of names)
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#
# Please cite your use of MDAnalysis in published work:
#
# R. J. Gowers, M. Linke, J. Barnoud, T. J. E. Reddy, M. N. Melo, S. L. Seyler,
# D. L. Dotson, J. Domanski, S. Buchoux, I. M. Kenney, and O. Beckstein.
# MDAnalysis: A Python package for the rapid analysis of molecular dynamics
# simulations. In S. Benthall and S. Rostrup editors, Proceedings of the 15th
# Python in Science Conference, pages 102-109, Austin, TX, 2016. SciPy.
# doi: 10.25080/majora-629e541a-00e
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# N. Michaud-Agrawal, E. J. Denning, T. B. Woolf, and O. Beckstein.
# MDAnalysis: A Toolkit for the Analysis of Molecular Dynamics Simulations.
# J. Comput. Chem. 32 (2011), 2319--2327, doi:10.1002/jcc.21787
#


# TPR parser and tpr support module
# Copyright (c) 2011 Zhuyi Xue
# Released under the  Lesser GNU Public Licence, v2.1+

"""
Utilities for the TPRParser
===========================

Function calling order::

   (TPRParser.py call do_mtop)
   do_mtop -> do_symtab
           -> do_ffparams -> do_iparams
           -> do_moltype  -> do_atoms  -> do_atom
                                       -> do_resinfo
                          -> do_ilists
                          -> do_block
                          -> do_blocka
           -> do_molblock

Then compose the stuffs in the format :class:`MDAnalysis.Universe` reads in.

The module also contains the :func:`do_inputrec` to read the TPR header with.
"""

import numpy as np
from mda_xdrlib import xdrlib
import struct

from . import obj
from . import setting
from ..base import squash_by
from ...core.topology import Topology
from ...core.topologyattrs import (
    Atomids,
    Atomnames,
    Atomtypes,
    Masses,
    Charges,
    Elements,
    Resids,
    Resnames,
    Moltypes,
    Molnums,
    Segids,
    ChainIDs,
    Bonds,
    Angles,
    Dihedrals,
    Impropers,
)


[docs] class TPXUnpacker(xdrlib.Unpacker): """ Extend the standard XDR unpacker for the specificity of TPX files. """ def __init__(self, data): super().__init__(data) self._buf = self.get_buffer() # The parent class uses a dunder attribute to store the # cursor position. This property makes it easier to manipulate # this attribute that is otherwise "protected". @property def _pos(self): return self.get_position() @_pos.setter def _pos(self, value): self.set_position(value) def _unpack_value(self, item_size, struct_template): start_position = self._pos end_position = self._pos = start_position + item_size content = self._buf[start_position:end_position] if len(content) != item_size: raise EOFError return struct.unpack(struct_template, content)[0]
[docs] def unpack_int64(self): return self._unpack_value(8, '>q')
[docs] def unpack_uint64(self): return self._unpack_value(8, '>Q')
[docs] def unpack_ushort(self): return self.unpack_uint()
[docs] def unpack_uchar(self): # TPX files prior to gromacs 2020 (tpx version < 119) use unsigned ints # (4 bytes) instead of unsigned chars. return self._unpack_value(4, '>I')
[docs] def do_string(self): """ Emulate gmx_fio_do_string gmx_fio_do_string reads a string from a XDR file. On the contrary to the python unpack_string, gmx_fio_do_string reads the size as an unsigned integer before reading the actual string. See <gromacs-2016-src>/src/gromacs/fileio/gmx_system_xdr.c:454 """ self.unpack_int() return self.unpack_string()
[docs] class TPXUnpacker2020(TPXUnpacker): """ Unpacker for TPX files from and later than gromacs 2020. A new implementation of the serializer (InMemorySerializer), introduced in gromacs 2020, changes le meaning of some types in the file body (the header keep using the previous implementation of the serializer). """
[docs] @classmethod def from_unpacker(cls, unpacker): new_unpacker = cls(unpacker.get_buffer()) new_unpacker._pos = unpacker.get_position() if hasattr(unpacker, 'unpack_real'): if unpacker.unpack_real == unpacker.unpack_float: new_unpacker.unpack_real = new_unpacker.unpack_float elif unpacker.unpack_real == unpacker.unpack_double: new_unpacker.unpack_real = new_unpacker.unpack_double else: raise ValueError("Unrecognized precision") return new_unpacker
[docs] def unpack_fstring(self, n): if n < 0: raise ValueError('Size of fstring cannot be negative.') start_position = self._pos end_position = self._pos = start_position + n if end_position > len(self._buf): raise EOFError content = self._buf[start_position:end_position] return content
[docs] def unpack_ushort(self): # The InMemorySerializer implements ushort according to the XDR standard # on the contrary to the IO serializer. return self._unpack_value(2, '>H')
[docs] def unpack_uchar(self): # The InMemorySerializer implements uchar according to the XDR standard # on the contrary to the IO serializer. return self._unpack_value(1, '>B')
[docs] def do_string(self): """ Emulate gmx_fio_do_string """ n = self.unpack_uint64() return self.unpack_fstring(n)
[docs] def ndo_int(data, n): """mimic of gmx_fio_ndo_real in gromacs""" return [data.unpack_int() for i in range(n)]
[docs] def ndo_real(data, n): """mimic of gmx_fio_ndo_real in gromacs""" return [data.unpack_real() for i in range(n)]
[docs] def do_rvec(data): return data.unpack_farray(setting.DIM, data.unpack_real)
[docs] def ndo_rvec(data, n): """mimic of gmx_fio_ndo_rvec in gromacs""" return [data.unpack_farray(setting.DIM, data.unpack_real) for i in range(n)]
[docs] def ndo_ivec(data, n): """mimic of gmx_fio_ndo_rvec in gromacs""" return [data.unpack_farray(setting.DIM, data.unpack_int) for i in range(n)]
[docs] def fileVersion_err(fver): if fver not in setting.SUPPORTED_VERSIONS: raise NotImplementedError( f"Your tpx version is {fver}, which this parser does not support, yet " )
[docs] def define_unpack_real(prec, data): """Define an unpack_real method of data based on the float precision used""" if prec == 4: data.unpack_real = data.unpack_float elif prec == 8: data.unpack_real = data.unpack_double else: raise ValueError(f"unsupported precision: {prec}")
[docs] def read_tpxheader(data): """this function is now compatible with do_tpxheader in tpxio.cpp """ # Last compatibility check with gromacs-2016 ver_str = data.do_string() # version string e.g. VERSION 4.0.5 if not ver_str.startswith(b'VERSION'): raise ValueError('Input does not look like a TPR file.') precision = data.unpack_int() # e.g. 4 define_unpack_real(precision, data) fileVersion = data.unpack_int() # version of tpx file fileVersion_err(fileVersion) # This is for backward compatibility with development version 77-79 where # the tag was, mistakenly, placed before the generation. # These versions are development versions between the 4.5 and 4.6 series. if 77 <= fileVersion <= 79: data.unpack_int() # the value is 8, but haven't found the file_tag = data.do_string() fileGeneration = data.unpack_int() if fileVersion >= 26 else 0 # generation of tpx file, e.g. 17 # Versions before 77 don't have the tag, set it to TPX_TAG_RELEASE file_tag # file_tag is used for comparing with tpx_tag. Only tpr files with a # tpx_tag from a lower or the same version of gromacs code can be parsed by # the tpxio.c file_tag = data.do_string() if fileVersion >= 81 else setting.TPX_TAG_RELEASE natoms = data.unpack_int() # total number of atoms ngtc = data.unpack_int() if fileVersion >= 28 else 0 # number of groups for T-coupling if fileVersion < 62: # not sure what these two are for. data.unpack_int() # idum data.unpack_real() # rdum fep_state = data.unpack_int() if fileVersion >= 79 else 0 # actually, it's lambda, not sure what is it. us lamb because lambda is a # keyword in python lamb = data.unpack_real() bIr = data.unpack_int() # has input record or not bTop = data.unpack_int() # has topology or not bX = data.unpack_int() # has coordinates or not bV = data.unpack_int() # has velocity or not bF = data.unpack_int() # has force or not bBox = data.unpack_int() # has box or not sizeOfTprBody = None if fileVersion >= setting.tpxv_AddSizeField and fileGeneration >= 27: sizeOfTprBody = data.unpack_int64() th = obj.TpxHeader(ver_str, precision, fileVersion, fileGeneration, file_tag, natoms, ngtc, fep_state, lamb, bIr, bTop, bX, bV, bF, bBox, sizeOfTprBody) return th
[docs] def extract_box_info(data, fver): box = ndo_rvec(data, setting.DIM) box_rel = ndo_rvec(data, setting.DIM) box_v = ndo_rvec(data, setting.DIM) return obj.Box(box, box_rel, box_v)
[docs] def do_mtop(data, fver, tpr_resid_from_one=False): # mtop: the topology of the whole system symtab = do_symtab(data) do_symstr(data, symtab) # system_name do_ffparams(data, fver) # params nmoltype = data.unpack_int() moltypes = [] # non-gromacs for i in range(nmoltype): moltype = do_moltype(data, symtab, fver) moltypes.append(moltype) nmolblock = data.unpack_int() mtop = obj.Mtop(nmoltype, moltypes, nmolblock) bonds = [] angles = [] dihedrals = [] impropers = [] atomids = [] segids = [] chainIDs = [] resids = [] resnames = [] atomnames = [] atomtypes = [] moltypes = [] molnums = [] charges = [] masses = [] elements = [] atom_start_ndx = 0 res_start_ndx = 0 molnum = 0 for i in range(mtop.nmolblock): # molb_type is just an index for moltypes/molecule_types mb = do_molblock(data) # segment is made to correspond to the molblock as in gromacs, the # naming is kind of arbitrary molblock = mtop.moltypes[mb.molb_type].name.decode('utf-8') segid = f"seg_{i}_{molblock}" chainID = molblock[14:] if molblock[:14] == "Protein_chain_" else molblock for j in range(mb.molb_nmol): mt = mtop.moltypes[mb.molb_type] # mt: molecule type for atomkind in mt.atomkinds: atomids.append(atomkind.id + atom_start_ndx) segids.append(segid) chainIDs.append(chainID) resids.append(atomkind.resid + res_start_ndx) resnames.append(atomkind.resname.decode()) atomnames.append(atomkind.name.decode()) atomtypes.append(atomkind.type.decode()) moltypes.append(molblock) molnums.append(molnum) charges.append(atomkind.charge) masses.append(atomkind.mass) elements.append(atomkind.element_symbol) molnum += 1 # remap_ method returns [blah, blah, ..] or [] bonds.extend(mt.remap_bonds(atom_start_ndx)) angles.extend(mt.remap_angles(atom_start_ndx)) dihedrals.extend(mt.remap_dihe(atom_start_ndx)) impropers.extend(mt.remap_impr(atom_start_ndx)) atom_start_ndx += mt.number_of_atoms() res_start_ndx += mt.number_of_residues() atomids = Atomids(np.array(atomids, dtype=np.int32)) atomnames = Atomnames(np.array(atomnames, dtype=object)) atomtypes = Atomtypes(np.array(atomtypes, dtype=object)) charges = Charges(np.array(charges, dtype=np.float32)) masses = Masses(np.array(masses, dtype=np.float32)) moltypes = np.array(moltypes, dtype=object) molnums = np.array(molnums, dtype=np.int32) segids = np.array(segids, dtype=object) chainIDs = np.array(chainIDs, dtype=object) resids = np.array(resids, dtype=np.int32) if tpr_resid_from_one: resids += 1 resnames = np.array(resnames, dtype=object) (residx, new_resids, (new_resnames, new_moltypes, new_molnums, perres_segids ) ) = squash_by(resids, resnames, moltypes, molnums, segids) residueids = Resids(new_resids) residuenames = Resnames(new_resnames) residue_moltypes = Moltypes(new_moltypes) residue_molnums = Molnums(new_molnums) segidx, perseg_segids = squash_by(perres_segids)[:2] segids = Segids(perseg_segids) chainIDs = ChainIDs(chainIDs) top = Topology( len(atomids), len(new_resids), len(perseg_segids), attrs=[ atomids, atomnames, atomtypes, charges, masses, residueids, residuenames, residue_moltypes, residue_molnums, segids, chainIDs, ], atom_resindex=residx, residue_segindex=segidx, ) top.add_TopologyAttr(Bonds([bond for bond in bonds if bond])) top.add_TopologyAttr(Angles([angle for angle in angles if angle])) top.add_TopologyAttr(Dihedrals([dihedral for dihedral in dihedrals if dihedral])) top.add_TopologyAttr(Impropers([improper for improper in impropers if improper])) if any(elements): elements = Elements(np.array(elements, dtype=object)) top.add_TopologyAttr(elements) return top
[docs] def do_symstr(data, symtab): # do_symstr: get a string based on index from the symtab ndx = data.unpack_int() return symtab[ndx]
[docs] def do_symtab(data): symtab_nr = data.unpack_int() # number of symbols symtab = [] for i in range(symtab_nr): j = data.do_string() symtab.append(j) return symtab
[docs] def do_ffparams(data, fver): atnr = data.unpack_int() ntypes = data.unpack_int() functype = ndo_int(data, ntypes) reppow = data.unpack_double() if fver >= 66 else 12.0 fudgeQQ = data.unpack_real() # mimicing the c code, # remapping the functype due to inconsistency in different versions for i in range(len(functype)): for k in setting.ftupd: # j[0]: tpx_version, j[1] funtype if fver < k[0] and functype[i] >= k[1]: functype[i] += 1 do_iparams(data, functype, fver) params = obj.Params(atnr, ntypes, functype, reppow, fudgeQQ) return params
[docs] def do_harm(data): data.unpack_real() # rA data.unpack_real() # krA data.unpack_real() # rB data.unpack_real() # krB
[docs] def do_iparams(data, functypes, fver): # Not all elif cases in this function has been used and tested for k, i in enumerate(functypes): if i in [ setting.F_ANGLES, setting.F_G96ANGLES, setting.F_BONDS, setting.F_G96BONDS, setting.F_HARMONIC, setting.F_IDIHS ]: do_harm(data) elif i in [setting.F_RESTRANGLES]: data.unpack_real() # harmonic.rA data.unpack_real() # harmonic.krA elif i in [setting.F_LINEAR_ANGLES]: data.unpack_real() # linangle.klinA data.unpack_real() # linangle.aA data.unpack_real() # linangle.klinB data.unpack_real() # linangle.aB); elif i in [setting.F_FENEBONDS]: data.unpack_real() # fene.bm data.unpack_real() # fene.kb elif i in [setting.F_RESTRBONDS]: data.unpack_real() # restraint.lowA data.unpack_real() # restraint.up1A data.unpack_real() # restraint.up2A data.unpack_real() # restraint.kA data.unpack_real() # restraint.lowB data.unpack_real() # restraint.up1B data.unpack_real() # restraint.up2B data.unpack_real() # restraint.kB elif i in [ setting.F_TABBONDS, setting.F_TABBONDSNC, setting.F_TABANGLES, setting.F_TABDIHS, ]: data.unpack_real() # tab.kA data.unpack_int() # tab.table data.unpack_real() # tab.kB elif i in [setting.F_CROSS_BOND_BONDS]: data.unpack_real() # cross_bb.r1e data.unpack_real() # cross_bb.r2e data.unpack_real() # cross_bb.krr elif i in [setting.F_CROSS_BOND_ANGLES]: data.unpack_real() # cross_ba.r1e data.unpack_real() # cross_ba.r2e data.unpack_real() # cross_ba.r3e data.unpack_real() # cross_ba.krt elif i in [setting.F_UREY_BRADLEY]: data.unpack_real() # u_b.theta data.unpack_real() # u_b.ktheta data.unpack_real() # u_b.r13 data.unpack_real() # u_b.kUB if fver >= 79: data.unpack_real() # u_b.thetaB data.unpack_real() # u_b.kthetaB data.unpack_real() # u_b.r13B data.unpack_real() # u_b.kUBB elif i in [setting.F_QUARTIC_ANGLES]: data.unpack_real() # qangle.theta ndo_real(data, 5) # qangle.c elif i in [setting.F_BHAM]: data.unpack_real() # bham.a data.unpack_real() # bham.b data.unpack_real() # bham.c elif i in [setting.F_MORSE]: data.unpack_real() # morse.b0 data.unpack_real() # morse.cb data.unpack_real() # morse.beta if fver >= 79: data.unpack_real() # morse.b0B data.unpack_real() # morse.cbB data.unpack_real() # morse.betaB elif i in [setting.F_CUBICBONDS]: data.unpack_real() # cubic.b0g data.unpack_real() # cubic.kb data.unpack_real() # cubic.kcub elif i in [setting.F_CONNBONDS]: pass elif i in [setting.F_POLARIZATION]: data.unpack_real() # polarize.alpha elif i in [setting.F_ANHARM_POL]: data.unpack_real() # anharm_polarize.alpha data.unpack_real() # anharm_polarize.drcut data.unpack_real() # anharm_polarize.khyp elif i in [setting.F_WATER_POL]: data.unpack_real() # wpol.al_x data.unpack_real() # wpol.al_y data.unpack_real() # wpol.al_z data.unpack_real() # wpol.rOH data.unpack_real() # wpol.rHH data.unpack_real() # wpol.rOD elif i in [setting.F_THOLE_POL]: data.unpack_real() # thole.a data.unpack_real() # thole.alpha1 data.unpack_real() # thole.alpha2 if fver < setting.tpxv_RemoveTholeRfac: data.unpack_real() # thole.rfac elif i in [setting.F_LJ]: data.unpack_real() # lj_c6 data.unpack_real() # lj_c9 elif i in [setting.F_LJ14]: data.unpack_real() # lj14_c6A data.unpack_real() # lj14_c12A data.unpack_real() # lj14_c6B data.unpack_real() # lj14_c12B elif i in [setting.F_LJC14_Q]: data.unpack_real() # ljc14.fqq data.unpack_real() # ljc14.qi data.unpack_real() # ljc14.qj data.unpack_real() # ljc14.c6 data.unpack_real() # ljc14.c12 elif i in [setting.F_LJC_PAIRS_NB]: data.unpack_real() # ljcnb.qi data.unpack_real() # ljcnb.qj data.unpack_real() # ljcnb.c6 data.unpack_real() # ljcnb.c12 elif i in [ setting.F_PIDIHS, setting.F_ANGRES, setting.F_ANGRESZ, setting.F_PDIHS, ]: data.unpack_real() # pdihs_phiA data.unpack_real() # pdihs_cpA data.unpack_real() # pdihs_phiB data.unpack_real() # pdihs_cpB data.unpack_int() # pdihs_mult elif i in [setting.F_RESTRDIHS]: data.unpack_real() # pdihs.phiA data.unpack_real() # pdihs.cpA elif i in [setting.F_DISRES]: data.unpack_int() # disres.label data.unpack_int() # disres.type data.unpack_real() # disres.low data.unpack_real() # disres.up1 data.unpack_real() # disres.up2 data.unpack_real() # disres.kfac elif i in [setting.F_ORIRES]: data.unpack_int() # orires.ex data.unpack_int() # orires.label data.unpack_int() # orires.power data.unpack_real() # orires.c data.unpack_real() # orires.obs data.unpack_real() # orires.kfac elif i in [setting.F_DIHRES]: if fver < 72: data.unpack_int() # idum data.unpack_int() # idum data.unpack_real() # dihres.phiA data.unpack_real() # dihres.dphiA data.unpack_real() # dihres.kfacA if fver >= 72: data.unpack_real() # dihres.phiB data.unpack_real() # dihres.dphiB data.unpack_real() # dihres.kfacB elif i in [setting.F_POSRES]: do_rvec(data) # posres.pos0A do_rvec(data) # posres.fcA do_rvec(data) # posres.pos0B do_rvec(data) # posres.fcB elif i in [setting.F_FBPOSRES]: data.unpack_int() # fbposres.geom do_rvec(data) # fbposres.pos0 data.unpack_real() # fbposres.r data.unpack_real() # fbposres.k elif i in [setting.F_CBTDIHS]: ndo_real(data, setting.NR_CBTDIHS) # cbtdihs.cbtcA elif i in [setting.F_RBDIHS]: ndo_real(data, setting.NR_RBDIHS) # iparams_rbdihs_rbcA ndo_real(data, setting.NR_RBDIHS) # iparams_rbdihs_rbcB elif i in [setting.F_FOURDIHS]: # Fourier dihedrals ndo_real(data, setting.NR_RBDIHS) # rbdihs.rbcA ndo_real(data, setting.NR_RBDIHS) # rbdihs.rbcB elif i in [setting.F_CONSTR, setting.F_CONSTRNC]: data.unpack_real() # dA data.unpack_real() # dB elif i in [setting.F_SETTLE]: data.unpack_real() # settle.doh data.unpack_real() # settle.dhh elif i in [setting.F_VSITE1]: pass elif i in [setting.F_VSITE2, setting.F_VSITE2FD]: data.unpack_real() # vsite.a elif i in [setting.F_VSITE3, setting.F_VSITE3FD, setting.F_VSITE3FAD]: data.unpack_real() # vsite.a data.unpack_real() # vsite.b elif i in [setting.F_VSITE3OUT, setting.F_VSITE4FD, setting.F_VSITE4FDN]: data.unpack_real() # vsite.a data.unpack_real() # vsite.b data.unpack_real() # vsite.c elif i in [setting.F_VSITEN]: data.unpack_int() # vsiten.n data.unpack_real() # vsiten.a elif i in [setting.F_GB12, setting.F_GB13, setting.F_GB14]: # /* We got rid of some parameters in version 68 */ if fver < 68: data.unpack_real() # rdum data.unpack_real() # rdum data.unpack_real() # rdum data.unpack_real() # rdum data.unpack_real() # gb.sar data.unpack_real() # gb.st data.unpack_real() # gb.pi data.unpack_real() # gb.gbr data.unpack_real() # gb.bmlt elif i in [setting.F_CMAP]: data.unpack_int() # cmap.cmapA data.unpack_int() # cmap.cmapB else: raise NotImplementedError(f"unknown functype: {i}") return
[docs] def do_moltype(data, symtab, fver): molname = do_symstr(data, symtab) # key info: about atoms atoms_obj = do_atoms(data, symtab, fver) #### start: MDAnalysis specific atomkinds = [] for k, a in enumerate(atoms_obj.atoms): atomkinds.append(obj.AtomKind( k, atoms_obj.atomnames[k], atoms_obj.type[k], a.resind, atoms_obj.resnames[a.resind], a.m, a.q, a.atomnumber, )) #### end: MDAnalysis specific # key info: about bonds, angles, dih, improp dih. ilists = do_ilists(data, fver) #### start: MDAnalysis specific # these may not be available for certain molecules, e.g. tip4p bonds, angles, dihs, impr = [], [], [], [] for ilist in ilists: if ilist.nr > 0: ik_obj = obj.InteractionKind(*ilist.ik) ias = ilist.iatoms # the following if..elif..else statement needs to be updated as new # type of interactions become interested if ik_obj.name in ['BONDS', 'G96BONDS', 'MORSE', 'CUBICBONDS', 'CONNBONDS', 'HARMONIC', 'FENEBONDS', 'RESTRAINTPOT', 'CONSTR', 'CONSTRNC', 'TABBONDS', 'TABBONDSNC']: bonds += list(ik_obj.process(ias)) elif ik_obj.name in ['ANGLES', 'G96ANGLES', 'CROSS_BOND_BOND', 'CROSS_BOND_ANGLE', 'UREY_BRADLEY', 'QANGLES', 'RESTRANGLES', 'TABANGLES']: angles += list(ik_obj.process(ias)) elif ik_obj.name in ['PDIHS', 'RBDIHS', 'RESTRDIHS', 'CBTDIHS', 'FOURDIHS', 'TABDIHS']: dihs += list(ik_obj.process(ias)) elif ik_obj.name in ['IDIHS', 'PIDIHS']: impr += list(ik_obj.process(ias)) elif ik_obj.name == 'SETTLE': # SETTLE interactions are optimized triangular constraints for # water molecules. They should be counted as a pair of bonds # between the oxygen and the hydrogens. In older versions of # the TPR format only specifies the index of the oxygen and # assumes that the next two atoms are the hydrogens. if len(ias) == 2: # Old format. Only the first atom is specified. base_atom = ias[1] bonds += [ [base_atom, base_atom + 1], [base_atom, base_atom + 2], ] else: all_settle = ik_obj.process(ias) for settle in all_settle: base_atom = settle[0] bonds += [ [settle[0], settle[1]], [settle[0], settle[2]], ] else: # other interaction types are not interested at the moment pass bonds = bonds if bonds else None angles = angles if angles else None dihs = dihs if dihs else None impr = impr if impr else None moltype = obj.MoleculeKind(molname, atomkinds, bonds, angles, dihs, impr) #### end: MDAnalysis specific # info in do_block and do_blocka is not interesting, but has to be parsed # here so that all moltypes can be parsed properly do_block(data) do_blocka(data) return moltype
[docs] def do_atoms(data, symtab, fver): nr = data.unpack_int() # number of atoms in a particular molecule nres = data.unpack_int() # number of residues in a particular molecule atoms = [] for i in range(nr): A = do_atom(data, fver) atoms.append(A) # do_strstr atomnames = [symtab[i] for i in ndo_int(data, nr)] type = [symtab[i] for i in ndo_int(data, nr)] # e.g. opls_111 typeB = [symtab[i] for i in ndo_int(data, nr)] resnames = do_resinfo(data, symtab, fver, nres) return obj.Atoms(atoms, nr, nres, type, typeB, atomnames, resnames)
[docs] def do_resinfo(data, symtab, fver, nres): if fver < 63: resnames = [symtab[i] for i in ndo_int(data, nres)] else: resnames = [] for i in range(nres): resnames.append(symtab[data.unpack_int()]) data.unpack_int() data.unpack_uchar() return resnames
[docs] def do_atom(data, fver): m = data.unpack_real() # mass q = data.unpack_real() # charge mB = data.unpack_real() qB = data.unpack_real() tp = data.unpack_ushort() # type is a keyword in python typeB = data.unpack_ushort() ptype = data.unpack_int() # regular atom, virtual site or others resind = data.unpack_int() # index of residue atomnumber = data.unpack_int() # index of atom type return obj.Atom(m, q, mB, qB, tp, typeB, ptype, resind, atomnumber)
[docs] def do_ilists(data, fver): nr = [] # number of ilist iatoms = [] # atoms involved in a particular interaction type pos = [] for j in range(setting.F_NRE): # total number of energies (i.e. interaction types) bClear = False for k in setting.ftupd: if fver < k[0] and j == k[1]: bClear = True if bClear: nr.append(0) iatoms.append(None) else: # do_ilist n = data.unpack_int() nr.append(n) l_ = [] for i in range(n): l_.append(data.unpack_int()) iatoms.append(l_) return [ obj.Ilist(n, it, i) for n, it, i in zip(nr, setting.interaction_types, iatoms) ]
[docs] def do_molblock(data): molb_type = data.unpack_int() molb_nmol = data.unpack_int() # number of moles in the molblock molb_natoms_mol = data.unpack_int() # number of atoms in a molecule molb_nposres_xA = data.unpack_int() if molb_nposres_xA > 0: ndo_rvec(data, molb_nposres_xA) molb_nposres_xB = data.unpack_int() # The number of posres coords for top B if molb_nposres_xB > 0: ndo_rvec(data, molb_nposres_xB) return obj.Molblock(molb_type, molb_nmol, molb_natoms_mol, molb_nposres_xA, molb_nposres_xB)
[docs] def do_block(data): block_nr = data.unpack_int() # for cgs: charge groups # starting or ending atom indices, based on which cgs are grouped ndo_int(data, block_nr + 1) return do_block
[docs] def do_blocka(data): block_nr = data.unpack_int() # No. of atoms with excls block_nra = data.unpack_int() # total times fo appearance of atoms for excls ndo_int(data, block_nr + 1) ndo_int(data, block_nra) return block_nr, block_nra