spatiallink

5reg

spatiallink

A spatial link packet

Content Model
    spatiallink ::= (&xml-component;*,
                     &xml-tag;*,
                     &packetsyn1;
                     &packetsyn2;
                     &packetsyn3;
                     &packetsyn4;
                     &packetsyn5;*)
Attributes
Name | Type
`radius` | `NUMBER` (required)
&packetattrlist2col;

&eltaddedver;7.4

## Description

This represents a spatial link packet, one of the many types of packet that together form the packet tree that a user sees when they open a ®ina; data file.

A spatial link packet stores a specific embedding of an oriented link in 3-dimensional space. Whereas &xml-link; stores purely combinatorial data (encoding the combinatorics of a link diagram), this spatial link packet stores purely geometric data (encoding specific paths through 3-space).

Each link component is stored as a closed path through 3-dimensional space, encoded in its own child &xml-component; element.

&packetchilddesc;

### Parents

&packetparents;

### Children

The following elements occur in `spatiallink`, and are specific to the spatial link packet type:

- &xml-component;

. &packetchildren;

## Attributes

The following attributes are specific to spatial link packets:

`radius`

- Indicates the preferred radius to use when rendering the link. This is a floating point number, and must be strictly positive.

  ®ina; writes the radius using hexadecimal floating point format to ensure no loss of precision; however, any standard floating point format may be used.

&packetattrdesc;

## Example

The following &xml; snippet shows part of a trefoil that was imported from &knotplot;:

    <spatiallink label="Trefoil">
      <component>
      <node> -0x1.404e48p+2 -0x1.19fb74p+1 0x1.57163p-1 </node>
      <node> -0x1.387c38p+2 -0x1.8d0064p+1 -0x1.7c7952p-4 </node>
      <node> -0x1.18f84cp+2 -0x1.eb60c2p+1 -0x1.c253fcp-1 </node>
      ...
      <node> -0x1.2f779cp+2 -0x1.3d036p+0 0x1.4ee7eap+0 </node>
      </component>
    </spatiallink>