def init_atom(
self,
name,
coord,
b_factor,
occupancy,
altloc,
fullname,
serial_number=None,
element=None,
pqr_charge=None,
radius=None,
is_pqr=False,
):
"""Create a new Atom object.
Arguments:
- name - string, atom name, e.g. CA, spaces should be stripped
- coord - Numeric array (Float0, size 3), atomic coordinates
- b_factor - float, B factor
- occupancy - float
- altloc - string, alternative location specifier
- fullname - string, atom name including spaces, e.g. " CA "
- element - string, upper case, e.g. "HG" for mercury
- pqr_charge - float, atom charge (PQR format)
- radius - float, atom radius (PQR format)
- is_pqr - boolean, flag to specify if a .pqr file is being parsed
"""
residue = self.residue
# if residue is None, an exception was generated during
# the construction of the residue
if residue is None:
return
# First check if this atom is already present in the residue.
# If it is, it might be due to the fact that the two atoms have atom
# names that differ only in spaces (e.g. "CA.." and ".CA.",
# where the dots are spaces). If that is so, use all spaces
# in the atom name of the current atom.
if residue.has_id(name):
duplicate_atom = residue[name]
# atom name with spaces of duplicate atom
duplicate_fullname = duplicate_atom.get_fullname()
if duplicate_fullname != fullname:
# name of current atom now includes spaces
name = fullname
warnings.warn(
"Atom names %r and %r differ only in spaces at line %i."
% (duplicate_fullname, fullname, self.line_counter),
PDBConstructionWarning,
)
if not is_pqr:
self.atom = Atom(
name,
coord,
b_factor,
occupancy,
altloc,
fullname,
serial_number,
element,
)
elif is_pqr:
self.atom = Atom(
name,
coord,
None,
None,
altloc,
fullname,
serial_number,
element,
pqr_charge,
radius,
)
if altloc != " ":
# The atom is disordered
if residue.has_id(name):
# Residue already contains this atom
duplicate_atom = residue[name]
if duplicate_atom.is_disordered() == 2:
duplicate_atom.disordered_add(self.atom)
else:
# This is an error in the PDB file:
# a disordered atom is found with a blank altloc
# Detach the duplicate atom, and put it in a
# DisorderedAtom object together with the current
# atom.
residue.detach_child(name)
disordered_atom = DisorderedAtom(name)
residue.add(disordered_atom)
disordered_atom.disordered_add(self.atom)
disordered_atom.disordered_add(duplicate_atom)
residue.flag_disordered()
warnings.warn(
"WARNING: disordered atom found with blank altloc before "
"line %i.\n" % self.line_counter,
PDBConstructionWarning,
)
else:
# The residue does not contain this disordered atom
# so we create a new one.
disordered_atom = DisorderedAtom(name)
residue.add(disordered_atom)
# Add the real atom to the disordered atom, and the
# disordered atom to the residue
disordered_atom.disordered_add(self.atom)
residue.flag_disordered()
else:
# The atom is not disordered
residue.add(self.atom)
def test_empty_disordered(self):
"""Raise ValueError on center of mass calculation of empty DisorderedAtom."""
da = DisorderedAtom("dummy")
with self.assertRaises(ValueError):
da.center_of_mass()
def init_atom(self, name, coord, b_factor, occupancy, altloc, fullname,
serial_number=None, element=None):
"""
Initiate a new Atom object.
Arguments:
o name - string, atom name, e.g. CA, spaces should be stripped
o coord - Numeric array (Float0, size 3), atomic coordinates
o b_factor - float, B factor
o occupancy - float
o altloc - string, alternative location specifier
o fullname - string, atom name including spaces, e.g. " CA "
o element - string, upper case, e.g. "HG" for mercury
"""
residue=self.residue
# if residue is None, an exception was generated during
# the construction of the residue
if residue is None:
return
# First check if this atom is already present in the residue.
# If it is, it might be due to the fact that the two atoms have atom
# names that differ only in spaces (e.g. "CA.." and ".CA.",
# where the dots are spaces). If that is so, use all spaces
# in the atom name of the current atom.
if residue.has_id(name):
duplicate_atom=residue[name]
# atom name with spaces of duplicate atom
duplicate_fullname=duplicate_atom.get_fullname()
if duplicate_fullname!=fullname:
# name of current atom now includes spaces
name=fullname
warnings.warn("Atom names %r and %r differ "
"only in spaces at line %i."
% (duplicate_fullname, fullname,
self.line_counter),
PDBConstructionWarning)
atom=self.atom=Atom(name, coord, b_factor, occupancy, altloc,
fullname, serial_number, element)
if altloc!=" ":
# The atom is disordered
if residue.has_id(name):
# Residue already contains this atom
duplicate_atom=residue[name]
if duplicate_atom.is_disordered()==2:
duplicate_atom.disordered_add(atom)
else:
# This is an error in the PDB file:
# a disordered atom is found with a blank altloc
# Detach the duplicate atom, and put it in a
# DisorderedAtom object together with the current
# atom.
residue.detach_child(name)
disordered_atom=DisorderedAtom(name)
residue.add(disordered_atom)
disordered_atom.disordered_add(atom)
disordered_atom.disordered_add(duplicate_atom)
residue.flag_disordered()
warnings.warn("WARNING: disordered atom found "
"with blank altloc before line %i.\n"
% self.line_counter,
PDBConstructionWarning)
else:
# The residue does not contain this disordered atom
# so we create a new one.
disordered_atom=DisorderedAtom(name)
residue.add(disordered_atom)
# Add the real atom to the disordered atom, and the
# disordered atom to the residue
disordered_atom.disordered_add(atom)
residue.flag_disordered()
else:
# The atom is not disordered
residue.add(atom)
