Averages/Pythagorean means: Difference between revisions
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m (→{{header|Python}}: Applied pylint (-> minor spacing and parenthesis adjustments)) |
(→Haskell Three applicatively defined functions: Replaced liftM2 with liftA2) |
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====Three applicatively defined functions==== |
====Three applicatively defined functions==== |
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These three functions (each combining the length of a list with some kind of fold over the elements of that same list), all share the same general ''' |
These three functions (each combining the length of a list with some kind of fold over the elements of that same list), all share the same general '''liftA2''' structure. |
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<lang haskell>import |
<lang haskell>import Control.Applicative (liftA2) |
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import Data.List (genericLength) |
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-- ARITHMETIC, GEOMETRIC AND HARMONIC MEANS |
-- ARITHMETIC, GEOMETRIC AND HARMONIC MEANS --------------- |
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| ⚫ | |||
| ⚫ | |||
| ⚫ | |||
geometric = liftM2 (**) product ((1 /) . genericLength) |
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| ⚫ | |||
geometric = liftA2 (**) product ((1 /) . genericLength) |
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harmonic = liftA2 (/) genericLength (foldr ((+) . (1 /)) 0) |
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-- GENERIC -------------------------------------------------------- |
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liftM2 f g h = pure f <*> g <*> h |
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-- TEST |
-- TEST --------------------------------------------------- |
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xs :: [Double] |
xs :: [Double] |
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xs = [arithmetic, geometric, harmonic] <*> [[1 .. 10]] |
xs = [arithmetic, geometric, harmonic] <*> [[1 .. 10]] |
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, mappend "\n A >= G >= H is " $ -- |
, mappend "\n A >= G >= H is " $ -- |
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(show . and) $ zipWith (>=) xs (tail xs) |
(show . and) $ zipWith (>=) xs (tail xs) |
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] |
] |
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</lang> |
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{{Out}} |
{{Out}} |
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<pre>("Arithmetic",5.5)("Geometric",4.528728688116765)("Harmonic",3.414171521474055) |
<pre>("Arithmetic",5.5)("Geometric",4.528728688116765)("Harmonic",3.414171521474055) |
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