-- | Bill Alves.
module Music.Theory.Tuning.Db.Alves where

import Music.Theory.Tuning.Type {- hmt -}

{- | Ratios for 'harrison_ditone' (SCALA=pyth_12)

> import Music.Theory.Tuning {- hmt -}
> let c = [0,114,204,294,408,498,612,702,816,906,996,1110]
> map (round . ratio_to_cents) harrison_ditone_r == c

> import Music.Theory.Tuning.Scala {- hmt -}
> scl_find_ji (harrison_ditone_r ++ [2])
-}
harrison_ditone_r :: [Rational]
harrison_ditone_r :: [Rational]
harrison_ditone_r =
    [Rational
1,Rational
2187forall a. Fractional a => a -> a -> a
/Rational
2048 {- 256/243 -}
    ,Rational
9forall a. Fractional a => a -> a -> a
/Rational
8,Rational
32forall a. Fractional a => a -> a -> a
/Rational
27
    ,Rational
81forall a. Fractional a => a -> a -> a
/Rational
64
    ,Rational
4forall a. Fractional a => a -> a -> a
/Rational
3,Rational
729forall a. Fractional a => a -> a -> a
/Rational
512
    ,Rational
3forall a. Fractional a => a -> a -> a
/Rational
2,Rational
6561forall a. Fractional a => a -> a -> a
/Rational
4096 {- 128/81 -}
    ,Rational
27forall a. Fractional a => a -> a -> a
/Rational
16,Rational
16forall a. Fractional a => a -> a -> a
/Rational
9
    ,Rational
243forall a. Fractional a => a -> a -> a
/Rational
128]

-- | Ditone/pythagorean tuning, <http://www.billalves.com/porgitaro/ditonesettuning.html>
--
-- > tn_divisions harrison_ditone == 12
-- > tn_cents_i harrison_ditone == [0,114,204,294,408,498,612,702,816,906,996,1110]
harrison_ditone :: Tuning
harrison_ditone :: Tuning
harrison_ditone = Either [Rational] [Cents]
-> Maybe (Either Rational Cents) -> Tuning
Tuning (forall a b. a -> Either a b
Left [Rational]
harrison_ditone_r) forall a. Maybe a
Nothing