Read an arff file.
the name of the file
the data of the arff file. Each record corresponds to one attribute.
this contains informations about the arff file, like type and names
of attributes, the relation (name of the dataset), etc...
This function should be able to read most arff files. Not implemented
date type attributes
string type attributes
It can read files with numeric and nominal attributes.
It can read files with sparse data (? in the file).