[Haskell-beginners] convert to fixed length Int

Hi. In Haskell, how would I go about converting from a Double (or Float) type to a Data.Int.Int8, Data.Int.Int16, and so forth? (Of course, expecting rounding and damage to out of range values.) I was playing around with signal generation using trig functions (hence the floating types) but the actual output has to be Int16. -- frigidcode.com indicium.us