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Functions
ost.mol.alg.trajectory_analysis Namespace Reference

Functions

def smooth
def RMSD_Matrix_From_Traj
def PairwiseDistancesFromTraj
def DistanceMatrixFromPairwiseDistances
def DistRMSDFromTraj
def AverageDistanceMatrixFromTraj

Detailed Description

**This Module requires numpy**

This module contains functions to analyze trajectories, mainly 
similiraty measures baed on RMSDS and pairwise distances.

Author: Niklaus Johner (niklaus.johner@unibas.ch)

Function Documentation

def ost.mol.alg.trajectory_analysis.AverageDistanceMatrixFromTraj (   t,
  sele,
  first = 0,
  last = -1 
)
This function calcultes the distance between each pair of atoms
in **sele**, averaged over the trajectory **t**.

:param t: the trajectory
:param sele: the selection used to determine the atom pairs
:param first: the first frame of t to be used
:param last: the last frame of t to be used
:type t: :class:`~ost.mol.CoordGroupHandle`
:type sele: :class:`~ost.mol.EntityView`
:type first: :class:`int`
:type last: :class:`int`

:return: a numpy N\ :subscript:`pairs`\ xN\ :subscript:`pairs` matrix, where N\ :subscript:`pairs`
 is the number of atom pairs in **sele**.

Definition at line 230 of file trajectory_analysis.py.

def ost.mol.alg.trajectory_analysis.DistanceMatrixFromPairwiseDistances (   distances,
  p = 2 
)
This function calculates an distance matrix M(N\ :subscript:`frames`\ xN\ :subscript:`frames`\ ) from
the pairwise distances matrix D(N\ :subscript:`pairs`\ xN\ :subscript:`frames`\ ), where 
N\ :subscript:`frames` is the number of frames in the trajectory
and N\ :subscript:`pairs` the number of atom pairs.
M[i,j] is the distance between frame i and frame j
calculated as a p-norm of the differences in distances
from the two frames (distance-RMSD for p=2).

:param distances: a pairwise distance matrix as obtained from 
 :py:func:`~mol.alg.trajectory_analysis.PairwiseDistancesFromTraj`
:param p: exponent used for the p-norm.

:return: a numpy N\ :subscript:`frames`\ xN\ :subscript:`frames` matrix, where N\ :subscript:`frames`
 is the number of frames.

Definition at line 138 of file trajectory_analysis.py.

def ost.mol.alg.trajectory_analysis.DistRMSDFromTraj (   t,
  sele,
  ref_sele,
  radius = 7.0,
  average = False,
  seq_sep = 4,
  first = 0,
  last = -1 
)
This function calculates the distance RMSD from a trajectory.
The distances selected for the calculation are all the distances
between pair of atoms from residues that are at least **seq_sep** apart
in the sequence and that are smaller than **radius** in **ref_sel**.
The number and order of atoms in **ref_sele** and **sele** should be the same.

:param t: the trajectory
:param sele: the selection used to calculate the distance RMSD
:param ref_sele: the reference selection used to determine the atom pairs and reference distances
:param radius: the upper limit of distances in ref_sele considered for the calculation
:param seq_sep: the minimal sequence separation between atom pairs considered for the calculation 
:param average: use the average distance in the trajectory as reference instead of the distance obtained from ref_sele
:param first: the first frame of t to be used
:param last: the last frame of t to be used

:type t: :class:`~ost.mol.CoordGroupHandle`
:type sele: :class:`~ost.mol.EntityView`
:type ref_sele: :class:`~ost.mol.EntityView`
:type radius: :class:`float`
:type average: :class:`bool`
:type first: :class:`int`
:type last: :class:`int`
:type seq_sep: :class:`int`

:return: a numpy vecor dist_rmsd(N\ :subscript:`frames`).  

Definition at line 171 of file trajectory_analysis.py.

def ost.mol.alg.trajectory_analysis.PairwiseDistancesFromTraj (   t,
  sele,
  first = 0,
  last = -1,
  seq_sep = 1 
)
This function calculates the distances between any pair of atoms in **sele**  
with sequence separation larger than **seq_sep** from a trajectory **t**.
It return a matrix containing one line for each atom pair and N\ :subscript:`frames` columns, where
N\ :subscript:`frames` is the number of frames in the trajectory.

:param t: the trajectory
:param sele: the selection used to determine the atom pairs
:param first: the first frame of t to be used
:param last: the last frame of t to be used
:param seq_sep: The minimal sequence separation between atom pairs
:type t: :class:`~ost.mol.CoordGroupHandle`
:type sele: :class:`~ost.mol.EntityView`
:type first: :class:`int`
:type last: :class:`int`
:type seq_sep: :class:`int`

:return: a numpy N\ :subscript:`pairs`\ xN\ :subscript:`frames` matrix.

Definition at line 95 of file trajectory_analysis.py.

def ost.mol.alg.trajectory_analysis.RMSD_Matrix_From_Traj (   t,
  sele,
  first = 0,
  last = -1 
)
This function calculates a matrix M such that M[i,j] is the
RMSD (calculated on **sele**) between frames i and j of the trajectory **t**
aligned on sele.

:param t: the trajectory
:param sele: the selection used for alignment and RMSD calculation
:param first: the first frame of t to be used
:param last: the last frame of t to be used
:type t: :class:`~ost.mol.CoordGroupHandle`
:type sele: :class:`~ost.mol.EntityView`
:type first: :class:`int`
:type last: :class:`int`

:return: Returns a numpy N\ :subscript:`frames`\ xN\ :subscript:`frames` matrix, 
 where N\ :subscript:`frames` is the number of frames.

Definition at line 58 of file trajectory_analysis.py.

def ost.mol.alg.trajectory_analysis.smooth (   vec,
  n 
)

Definition at line 15 of file trajectory_analysis.py.