| varTensor |
index |
variable magnitude orientational tensor object
This object is usually constructed using the create_VarTensor() function in
the varTensorTools module. The VarTensor object is used by
rdcPot.RDCPot and csaPot.CSAPot potential terms.
The following parameters can be set [defaults in square brackets]
Da - axial tensor component. Setting this modifies ths position of
the p1 atom.
Rh - rhombic tensor component. Setting this modifies ths position of
the p2 atom.
DaMax - maximum possible value of Da [50]
verbose - if true, sporadically spit out info [False]
oAtom - origin atom
o2Atom - origin atom #2 (see below)
xAtom - x-axis atom
yAtom - y-axis atom
zAtom - z-axis atom
p1Atom - Da parameter atom
p2Atom - rhombicity parameter atom
potType - type of potential: "harmonic" or "square" ["harmonic"]
expts - the potentials (RDCPots and CSAPots) which depend on this
tensor.
freedom - string used by varTensorTools.topologySetup to setup IVM
topology. The freedom language contains the following keywords:
fix
fixAxis
fixDa, varyDa
fixRh, varyRh
fixAxisTo <name>
fixRhTo <name>
ignore
More than one can be specified, using a comma as a seperator.
useSimEnsWeight - whether to use the ensemble wieghts set with setEnsWeights
or to use those of the underlying EnsembleSimulation.
the above quantities may be retrieved using the member function form
quantity(), while they are set using the form setQuantity(value).
ensWeigth(index) - return the ensemble weight associated with the
specified member.
setEnsWeights(vals) - use the specified ensemble weights instead of those
in the underlying EnsembleSimulation.
if the associated Simulation object is an EnsembleSimulation, additional
functionality is available:
accessors:
ensembleAxis - boolean. If True, there is a separate value for tensor
axis orientation for each ensemble member. Default is False.
ensembleDa - boolean. If true, there is a separate value of Da for
each structure. Default is 0(false).
ensembleRh - boolean. If true, there is a separate value of rhombicity for
each structure. Default is 0(false).
scaleDa - weight on an energy term which weights spread in
Da. This is only meaningful if ensembleDa is on. [default: 0]
scaleRh - weight on an energy term which weights spread in
rhombicity. This is only meaningful if ensembleRh is on.
[default: 0]
spreadDa - Target spread in Da. Deviations in Da of less than
spreadDa (from the mean) do not count towards the Da
spread energy term. [default value: 0]
spreadRh - Target spread in rhombicity. Deviations in rhombicity
of less than spreadRh (from the mean) do not count
towards the rhombicity spread energy term. [default value: 0]
In addition the followiong methods are provided:
aveDa() - return the value of Da averaged over the
ensembleSimulation.EnsembleSimulation
aveRhombicity() - return the value of Rh averaged over the
ensembleSimulation.EnsembleSimulation
The energy term associated with spread in Da and Rh is
scaleDa * < harmonicSquare( Da - <Da> ) >
and
scaleRh * < harmonicSquare( Rh - <Rh> ) >,
respectively.
Implementation: required topology issues
The VarTensor object is best used with the IVM module for coordinate
minimization and manipulation. An example of such use is shown in the
rdcPotTest.py script in the python/tests subdirectory. To exploit the full
capabilities of the VarTensor object, seven atoms are used to represent
tensor properties. A second origin atom (named OO2) is placed
co-incident with atom OO.
The axial tensor component Da is represented as
Da_max * cos(theta1)
where theta1 is the angle defined by atomX-atomOO-atomPA1. The
rhombic tensor component is represented by
2/3 * sin(theta2)
where theta2 is the angle defined by atomZ-atomOO2-atomPA2.
# This file was automatically generated by SWIG (http://www.swig.org).
# Version 4.0.2
#
# Do not make changes to this file unless you know what you are doing--modify
# the SWIG interface file instead.
| Classes | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Functions | ||
| ||