Convert APResult (apcluster output) to dataframe

This can then be used for plots, clustering etc.

# S3 method for APResult
as.data.frame(x, row.names = NULL, optional = FALSE,
  clusters, ...)

Arguments

x	an `APResult` object.
row.names	ignored.
optional	logical. If `TRUE`, setting row names and converting column names (to syntactic names: see make.names) is optional.
clusters	a character vector of the names of the exemplars to include.
...	extra arguments to pass to `data.frame`.

A data.frame with columns exemplar, cluster, idx, item.