Converts the edges of the infection tree described in the
transmat object into a network object,
copying in appropriate edge attributes for 'at', 'infDur', 'transProb',
'actRate', and 'finalProb' and constructing a vertex attribute
for 'at'.
# S3 method for transmat
as.network(x, ...)an object of class transmat to be converted into a network
object
unused