packet (link)

Description

In Regina 6.0.1 and earlier, the packet element was used to store every packet in the entire packet tree that makes up a Regina data file. This page describes how the packet element was structured when storing a knot/link packet. Since Regina 7.0, each packet type has its own XML element; in particular, knot/link packets are now stored using the link element.

A knot/link packet stores the diagram of an oriented link in 3-dimensional space.

The number of crossings in the diagram and the signs of these crossings are stored in the child crossings element, and the connections between these crossings are stored in the child connections element. The child components element stores a starting point for each component of the link.

The roles played by the child tag and packet elements are described in the general packet element documentation.

Example

The following XML snippet represents the Whitehead link.

<packet label="Whitehead link" type="Link" typeid="17" parent="">
<crossings size="5">
- - + + -
</crossings>
<connections>
_1 ^1
_2 ^4
_4 ^3
_0 ^2
_3 ^0
</connections>
<components size="2">
^0 _0
</components>
</packet>