# Example for: Selection.rotate_dihedrals()

from modeller import *
from modeller.scripts import complete_pdb

# This will optimize and randomize dihedrals in a MODEL
env = Environ()
env.io.atom_files_directory = ['../atom_files']
env.libs.topology.read(file='$(LIB)/top_heav.lib')
env.libs.parameters.read(file='$(LIB)/par.lib')

# Select dihedral angle types for optimization and randomization:
dih = 'phi psi omega chi1 chi2 chi3 chi4 chi5'

# Read the sequence, get its topology and coordinates:
mdl = complete_pdb(env, '1fas')

# Select all atoms
atmsel = Selection(mdl)

atmsel.rotate_dihedrals(change='RANDOMIZE', deviation=90.0, dihedrals=dih)
mdl.write(file='1fas.ini1')

# Get restraints from somewhere and optimize dihedrals:
mdl.restraints.make(atmsel, restraint_type='stereo', spline_on_site=False)
atmsel.rotate_dihedrals(change='OPTIMIZE', deviation=90.0, dihedrals=dih)
mdl.write(file='1fas.ini2')