used as feature name prefix.
Featurize a single row.
Featurize a single row.
input row.
output indices.
output values.
this interface isn't very Scala-esce, but it avoids lots of allocation. Also due to SparseVector limitations we don't support 64bit indices (e.g. indices are signed 32bit ints)
input field index.
input field index.
bit mask applied to final hash.
pre-hashed namespace.
featurizer for value type.
Featurize map of type T into native VW structure. (hash(column name + k):value)
value type.