d normal distribution (mean = 0, stddev = 1) (from @Statistics.Distribution.Normal@)
-- 
-- > λ> mwc $ listOf 10 standard
-- > [ 0.2252627935262769,1.1831885443897947,-0.6577353418647461
-- > , 2.1574536855051853,-0.16983072710637676,0.9667954287638821
-- > , -1.8758605246293683,-0.8578048838241616,1.9516838769731923
-- > , 0.43752574431460434 ]
standard :: PrimMonad m
         => RandT m Double
standard = continuous N.standard

-- | Create a n
standard :: PrimMonad m
         => RandT m Double
standard = continuous N.standard
standard = continuous N.standard