View source for Extend (selection operator)

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This page is about a selection operator. For the API function with the same name, see [[extend]].
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The selection operator '''extend''' is part of the PyMOL selection language and grows an atom selection based on covalent bonds.

== Usage ==

 s1 extend X

Where '''s1''' is a selection expression and '''X''' is the number of bonds.

== Example ==

The behavior is illustrated on residue 64 of PDB file 1KAO where we initially select one atom and then "extend" that selection by one and three covalent bonds.

<table border=1 cellspacing=0>
<tr>
<td><source lang="python">select (resi 64 and name CZ)</source></td>
<td>[[Image:Extend0.png|250px]]</td>
</tr><tr>
<td><source lang="python">select (resi 64 and name CZ) extend 1</source></td>
<td>[[Image:Extend1.png|250px]]</td>
</tr><tr>
<td><source lang="python">select (resi 64 and name CZ) extend 3</source></td>
<td>[[Image:Extend3.png|250px]]</td>
</tr>
</table>

== See also ==

* [[Selection Algebra]]

[[Category:Selecting]]