Alter

DESCRIPTION

alter changes one or more atomic properties over a selection using the python evaluator with a separate name space for each atom. The symbols defined in the name space are:

name, resn, resi, chain, alt, elem, q, b, segi,
type (ATOM,HETATM), partial_charge, formal_charge,
text_type, numeric_type, ID, vdw

All strings must be explicitly quoted. This operation typically takes several seconds per thousand atoms altered.

WARNING: You should always issue a sort command on an object after modifying any property which might affect canonical atom ordering (names, chains, etc.). Failure to do so will confound subsequent "create" and "byres" operations.

USAGE

alter (selection),expression

EXAMPLES

• Change chain label and residue index

 alter (chain A),chain='B'
 alter (all),resi=str(int(resi)+100)
 sort

• Change van der Waals radius of a given atom

alter (name P), vdw=1.90

SEE ALSO

Cmd alter_state, Cmd iterate, Cmd iterate_state, Cmd sort