def atomsel(self):
"""
Returns respective 'VMD.atomsel' instance.
"""
if self._atomsel is None:
self._atomsel = _atomsel('segname "%s"' % self.name, frame=self._frame, molid=self._molecule.molid)
return self._atomsel
def atomsel(self):
"""
Returns respective 'VMD.atomsel' instance.
"""
if self._atomsel is None:
self._atomsel = _atomsel('residue %d' % self._index, frame=self._frame, molid=self._molecule.molid)
return self._atomsel
def __init__(self, selection, molecule=None, frame=NOW):
"""
Creates selection.
@param selection: Selection text
@param molecule: Molecule to select from. Top if not provider.
@type molecule: Molecule or None
@param frame: Selection frame
@type frame: Non-negative integer or NOW
"""
super(Selection, self).__init__(molecule=molecule, frame=frame)
self._selection = selection
# No need to delay creation of the atomsel. This also checks if the selection text makes sense.
self._atomsel = _atomsel(selection, frame=frame, molid=self._molecule.molid)
# _update_frame is the frame that have been used to filter coordinate based selection in last update.
self._update_frame = self._get_active_frame()
def pick(cls, selection, molecule=None, frame=NOW):
"""
Creates atom from selection text.
@param selection: Selection text
@param molecule: Molecule to select from. Top if not defined.
@type molecule: Molecule
@param frame: Atom's frame
@type frame: Non-negative integer or NOW
"""
if molecule is None:
molecule = MOLECULES.top
else:
assert isinstance(molecule, Molecule)
assert frame == NOW or frame >= 0
sel = _atomsel(selection, frame=frame, molid=molecule.molid)
if len(sel) != 1:
raise ValueError("Selection '%s' doesn't define single atom in '%s' at %s" % (selection, molecule, frame))
self = cls(sel.get('index')[0], molecule, frame)
return self