the data to be written, preferably a matrix or data frame.
If not, coercion to a data frame is attempted.
either a character string naming a file, or a connection.
"" indicates output to the standard output connection.
the character(s) to print at the end of each line (row).
The name of the relation to be written in the file.
relation will be passed through make.names before
writing to the file, in an attempt to it them acceptable to Weka, and
column names what do not start with an alphabetic character will have
However, the references say that ARFF files are ASCII files, and that
encoding is not enforced.