A tessellation on a linear network is a partition of the
network into non-overlapping pieces (tiles). Each tile consists of one
or more line segments which are subsets of the line segments making up
the network. A tile can consist of several disjoint pieces.
This function converts the tessellation x to a data frame.
Each row of the data frame specifies one sub-segment of the network,
and allocates it to a particular tile. The data frame has the
following columns:
The seg column specifies which line segment of the network
contains the sub-segment. Values of seg are integer indices
for the network segments in as.psp(as.linnet(x)).
The t0 and t1 columns specify the start and end points
of the sub-segment. They are numeric values between 0 and 1
inclusive, where the values 0 and 1 representing the network vertices
that are joined by this network segment.
The tile column specifies which tile of the tessellation
includes this sub-segment. It is a factor whose
levels are the names of the tiles.
The tessellation may have marks, which are attached to the tiles
of the tessellation. If marks are present, the resulting data frame
includes columns containing, for each sub-segment,
the mark value of the corresponding tile.