Iterate: Difference between revisions
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===DESCRIPTION=== | ===DESCRIPTION=== | ||
'''iterate''' iterates over an expression with a separate name space for each atom. However, unlike the "alter" command, atomic properties can not be altered. Thus, '''iterate''' is more efficient than '''alter'''. | |||
It can be used to perform operations and aggregations using atomic selections, and store the results in any global object, such as the predefined '''stored''' object. | |||
The local namespace for "iterate" contains the following names | |||
name, resn, resi, chain, alt, elem, | |||
q, b, segi, and type (ATOM,HETATM), | |||
partial_charge, formal_charge, | |||
text_type, numeric_type, ID | |||
All strings in the expression must be explicitly quoted. This operation typically takes a second per thousand atoms. | |||
===USAGE=== | |||
iterate (selection),expression | |||
===EXAMPLES=== | ===EXAMPLES=== | ||
<source lang="python"> | |||
stored.net_charge = 0 | |||
iterate (all),stored.net_charge = stored.net_charge + partial_charge | |||
stored.names = [] | |||
iterate (all),stored.names.append(name) | |||
</source> | |||
===SEE ALSO=== | ===SEE ALSO=== | ||
[[Cmd iterate_state]], [[Cmd alter]], [[Cmd alter_state]]] | |||
[[Category:Commands|iterate]] | [[Category:Commands|iterate]] | ||
Revision as of 22:22, 2 June 2005
DESCRIPTION
iterate iterates over an expression with a separate name space for each atom. However, unlike the "alter" command, atomic properties can not be altered. Thus, iterate is more efficient than alter.
It can be used to perform operations and aggregations using atomic selections, and store the results in any global object, such as the predefined stored object.
The local namespace for "iterate" contains the following names
name, resn, resi, chain, alt, elem, q, b, segi, and type (ATOM,HETATM), partial_charge, formal_charge, text_type, numeric_type, ID
All strings in the expression must be explicitly quoted. This operation typically takes a second per thousand atoms.
USAGE
iterate (selection),expression
EXAMPLES
stored.net_charge = 0
iterate (all),stored.net_charge = stored.net_charge + partial_charge
stored.names = []
iterate (all),stored.names.append(name)