Created unsafeUpdate, unsafeValueAt for DenseVector. These can significantly improve performance, though of course you need to manually do bounds checks. I.e., unsafeValueAt(-1) will fail.
Created VariableUFunc trait, bsaed on dlwh's suggestion here: https://github.com/scalanlp/breeze/issues/124#issuecomment-36537020
DensePolynomial pimp lets us treat polynomials as ufuncs.
Explanatory comment.
Polynomial works for matrices.
unused variable