selection.randomize_xyz() -- randomize selected coordinates

randomize_xyz(deviation)

This command randomizes the Cartesian coordinates of the selected atoms. If deviation is positive, the coordinates are randomized by the addition of a random number uniformly distributed in the interval from $-{\sf deviation}\index{deviation@{\sf deviation}}$ to $+{\sf deviation}\index{deviation@{\sf deviation}}$ angstroms. If deviation is negative, the coordinates are assigned a random value uniformly distributed in the interval from $-{\sf deviation}\index{deviation@{\sf deviation}}$ to $+{\sf deviation}\index{deviation@{\sf deviation}}$ angstroms.

Any defined rigid bodies (see Section 5.3.4) remain rigid; only their mass centers are modified by this command (no rotation is done).

Example: examples/commands/randomize_xyz.py

# Example for: selection.randomize_xyz()

# This will randomize the X,Y,Z of the model:

from modeller import *

env = environ()
env.io.atom_files_directory = '../atom_files'

mdl = model(env, file='1fas')

# Act on all atoms in the model
sel = selection(mdl)

# Change all existing X,Y,Z for +- 4 angstroms:
sel.randomize_xyz(deviation=4.0)
mdl.write(file='1fas.ini1')

# Assign X,Y,Z in the range from -100 to 100 angstroms:
sel.randomize_xyz(deviation=-100.0)
mdl.write(file='1fas.ini2')