Stem-and-leaf plot: Difference between revisions
Undo revision 260427 by Hout (talk)
Line 993:
=={{header|Haskell}}==
<lang haskell>import Data.List
import Control.Arrow
import Control.Monad
nlsRaw = "12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31"
++ " 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63"
++ " 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53"
++ " 114 96 25 109 7 31 141 46 13 27 43 117 116 27 7 68 40 31 115 124 42 128"
++ " 52 71 118 117 38 27 106 33 117 116 111 40 119 47 105 57 122 109 124 115"
++ " 43 120 43 27 27 18 28 48 125 107 114 34 133 45 120 30 127 31 116 146"
nls :: [Int]
nls = map read $ words nlsRaw
groupWith f = takeWhile(not.null). unfoldr(Just. (partition =<< (. f). (==). f. head))
justifyR = foldl ((. return) . (++) . tail) . flip replicate ' '
task ds = mapM_ (putStrLn. showStemLeaves justifyR fb. (head *** sort.concat). unzip)
$ groupWith fst $ stems ++ map (second return) stemLeaf
where stemLeaf = map (`quotRem` 10) ds
stems = map (flip(,)[]) $ uncurry enumFromTo $ minimum &&& maximum $ fst $ unzip stemLeaf
showStemLeaves f w (a,b) = f w (show a) ++ " |" ++ concatMap (f w. show) b
fb = length $ show $ maximum $ map abs ds</lang>
Output:
<pre>*Main> task nls
0 | 7 7
1 | 2 3 8 8
2 | 3 5 7 7 7 7 7 7 8 8 9 9
3 | 0 1 1 1 1 2 3 4 5 6 7 7 7 8 9
4 | 0 0 1 2 2 2 2 3 3 3 4 4 4 5 6 7 8 8
5 | 2 3 7 8 8
6 | 1 3 8
7 | 1
8 |
9 | 6 9
10 | 4 5 5 5 5 6 7 9 9 9
11 | 1 3 3 3 3 4 4 4 5 5 5 6 6 6 6 7 7 7 7 8 8 9 9
12 | 0 0 1 1 2 2 3 4 4 4 5 5 5 6 7 7 7 7 8 8
13 | 1 2 3 9
14 | 1 6</pre>
Or alternatively – aiming more for legibility than for economy or concision:
<lang haskell>import Data.List (groupBy, intersperse, mapAccumL, sortBy)
import Data.Ord (comparing)
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