a distribution (from @Statistics.Distribution.Gamma@)
-- 
-- > λ> mwc $ listOf 10 (gamma 3 0.1)
-- > [ 5.683745415884202e-2,0.20726188766138176,0.3150672538487696
-- > , 0.4250825346490057,0.5586516230326105,0.46897413151474315
-- > , 0.18374916962208182,9.93000480494153e-2,0.6057279704154832
-- > , 0.11070190282993911 ]
gamma :: PrimMonad m
      => Double -- ^ shape parameter k
      -> Double -- ^ scale parameter theta
      -> RandT m Double
gamma k theta = continuous $ gammaDistr k theta

-- | Gam
gamma :: PrimMonad m
      => Double -- ^ shape parameter k
      -> Double -- ^ scale parameter theta
      -> RandT m Double
gamma k theta = continuous $ gammaDistr k theta
gamma k theta = continuous $ gammaDistr k theta