src/Gargantext/Ngrams/FrequentItemSet.hs

   1 {-|
   2 Module      : Gargantext.Ngrams.FrequentItemSet
   3 Description : Ngrams tools
   4 Copyright   : (c) CNRS, 2018
   5 License     : AGPL + CECILL v3
   6 Maintainer  : team@gargantext.org
   7 Stability   : experimental
   8 Portability : POSIX
   9
  10 Domain Specific Language to manage Frequent Item Set (FIS)
  11
  12 -}
  13
  14 {-# LANGUAGE NoImplicitPrelude #-}
  15
  16 module Gargantext.Ngrams.FrequentItemSet
  17   ( Fis, Size
  18   , occ, cooc
  19   , all, between
  20   , module HLCM
  21   )
  22   where
  23
  24 import Data.List (tail, filter)
  25 import Data.Either
  26
  27 import HLCM
  28
  29 import Gargantext.Prelude
  30
  31 type Size = Either Int (Int, Int)
  32
  33 --data Size = Point | Segment
  34
  35 ------------------------------------------------------------------------
  36 -- | Occurrence is Frequent Item Set of size 1
  37 occ  :: Frequency -> [[Item]] -> [Fis]
  38 occ f is  = fisWithSize (Left 1) f is
  39
  40 -- | Cooccurrence is Frequent Item Set of size 2
  41 cooc :: Frequency -> [[Item]] -> [Fis]
  42 cooc f is = fisWithSize (Left 2) f is
  43
  44 all :: Frequency -> [[Item]] -> [Fis]
  45 all f is  = fisWith Nothing f is
  46
  47 ------------------------------------------------------------------------
  48 between :: (Int, Int) -> Frequency -> [[Item]] -> [Fis]
  49 between (x,y) f is = fisWithSize (Right (x,y)) f is
  50
  51 --maximum :: Int -> Frequency -> [[Item]] -> [Fis]
  52 --maximum m f is = between (0,m) f is
  53
  54
  55 ------------------------------------------------------------------------
  56 ------------------------------------------------------------------------
  57 -- | Data type to type the Frequent Item Set
  58 -- TODO replace List with Set in fisItemSet
  59 -- be careful : risks to erase HLCM behavior
  60 type Fis = Fis' Item
  61 data Fis' a = Fis' { _fisCount   :: Int
  62                    , _fisItemSet :: [a]
  63                    } deriving (Show)
  64
  65 -- | Sugar from items to FIS
  66 items2fis :: [Item] -> Maybe Fis
  67 items2fis is = case head is of
  68                  Nothing -> Nothing
  69                  Just h  -> Just (Fis' h (tail is))
  70
  71 ------------------------------------------------------------------------
  72 ------------------------------------------------------------------------
  73
  74 fisWithSize :: Size -> Frequency -> [[Item]] -> [Fis]
  75 fisWithSize n f is = case n of
  76   Left   n'   -> fisWith (Just (\x -> length x == (n'+1)    )) f is
  77   Right (a,b) -> fisWith (Just (\x -> cond1 a x && cond2 b x)) f is
  78                     where
  79                       cond1 a' x = length x >= a'
  80                       cond2 b' x = length x <= b'
  81
  82
  83 fisWith :: Maybe ([Item] -> Bool) -> Frequency -> [[Item]] -> [Fis]
  84 fisWith s f is = unMaybe $ map items2fis $ filter' $ runLCMmatrix is f
  85   where
  86     filter' = case s of
  87                 Nothing  -> identity
  88                 Just fun -> filter fun
  89
  90 ------------------------------------------------------------------------
  91 ------------------------------------------------------------------------