DenseMatrix array masking

[Rahul Palamuttam]

Hi I wanted to create masked arrays and wanted to know how to do this using the DenseMatrix syntax.

I was looking for something like DenseMatrix <= num. Which will give me another dense matrix of elements less than num, or 0 otherwise.

[David Hall]

it is not fast, but:

where(dm :<= num, dm, DenseMatrix.zeros[Double](dm.rows, dm.cols))

or 

dm.map { v => if (v <= num) v else 0.0 }

or 

dm :* I(dm :<= 5)