edge file

*   First line: <# of edges> <# of boundary markers (0 or 1)>
*   Following lines: <edge #> <endpoint> <endpoint> \[boundary marker\]

• Blank lines and comments prefixed by # may be placed anywhere.
• Edges are numbered consecutively, starting from one or zero.
• Endpoints are indices into the corresponding node file

note

Triangle can produce edge files (use the e switch), but cannot read them. The optional column of boundary markers is suppressed by the B switch.

In Voronoi diagram, one also finds a special kind of edge that is an infinite ray with only one endpoint. For these edges, a different format is used:

results

<edge #> <endpoint> -1 <direction x> <direction y>

Here, the direction is a floating-point vector that indicates the direction of the infinite ray.