[FEAT] Bridgeness (needs tests).

src/Gargantext/Prelude.hs

@@ -26,12 +26,14 @@ module Gargantext.Prelude
   , module Text.Read
   , cs
   , module Data.Maybe
+  , round
   , sortWith
   )
   where
 
 import GHC.Exts (sortWith)
 import GHC.Err.Located (undefined)
+import GHC.Real (round)
 import Control.Monad.IO.Class (MonadIO)
 import Data.Maybe (isJust, fromJust, maybe)
 import Protolude ( Bool(True, False), Int, Int64, Double, Integer

src/Gargantext/Text/Flow.hs

@@ -43,6 +43,7 @@ import Gargantext.Viz.Graph.Index (createIndices, toIndex, map2mat, mat2map)
 import Gargantext.Viz.Graph.Distances.Matrice (measureConditional)
 import Gargantext.Viz.Graph (Graph(..), data2graph)
 import Gargantext.Text.Metrics.Count (cooc)
+import Gargantext.Viz.Graph.Bridgeness (bridgeness)
 import Gargantext.Text.Metrics (filterCooc, FilterConfig(..), Clusters(..), SampleBins(..), DefaultValue(..), MapListSize(..), InclusionSize(..))
 import Gargantext.Text.Terms (TermType, extractTerms)
 import Gargantext.Text.Context (splitBy, SplitContext(Sentences))
@@ -168,5 +169,6 @@ cooc2graph myCooc = do
 -- Building : -> Graph -> JSON
   --printDebug "partitions" $ DS.size $ DS.fromList $ map (l_community_id) partitions
   --printDebug "partitions" partitions
-  pure $ data2graph (M.toList ti) myCooc4 distanceMap partitions
+  let distanceMap' = bridgeness 5 partitions distanceMap
+  pure $ data2graph (M.toList ti) myCooc4 distanceMap' partitions
 

src/Gargantext/Viz/Graph/Bridgeness.hs

+{-|
+Module      : Gargantext.Viz.Graph.Bridgeness
+Description : 
+Copyright   : (c) CNRS, 2017-Present
+License     : AGPL + CECILL v3
+Maintainer  : team@gargantext.org
+Stability   : experimental
+Portability : POSIX
+
+
+-}
+
+{-# LANGUAGE NoImplicitPrelude #-}
+
+module Gargantext.Viz.Graph.Bridgeness (bridgeness)
+  where
+
+import Gargantext.Prelude
+--import Gargantext.Viz.Graph
+import Data.Map (Map, fromListWith, lookup, fromList, keys)
+import Data.Maybe (catMaybes)
+import Data.List (sortOn, concat)
+import Data.Graph.Clustering.Louvain.CplusPlus (LouvainNode(..))
+
+type Bridgeness = Double
+
+-- TODO mv in Louvain Lib
+type LouvainNodeId = Int
+type CommunityId   = Int
+
+partition2map :: [LouvainNode] -> Map CommunityId [LouvainNodeId]
+partition2map ns = fromListWith (<>) [ (cId, [nId]) | LouvainNode nId cId <- ns]
+
+ordEdgesBetween :: (Ord distance, Ord node)
+                => [node] -> [node]
+                -> Map (node, node) distance
+                -> [((node, node), distance)]
+ordEdgesBetween c1 c2 d = reverse $ sortOn snd $ catMaybes
+              [ (,) <$> Just   (n1,n2)
+                    <*> lookup (n1,n2) d
+              | n1 <- c1
+              , n2 <- c2
+              , n1 < n2
+              ]
+
+filterEdgesBetween :: (RealFrac b, Ord node, Ord distance) =>
+     b -> [node] -> [node]
+     -> Map (node, node) distance
+     -> [((node, node), distance)]
+filterEdgesBetween b c1 c2 d = take n d'
+  where
+    n  = round $ b * i / (s1 + s2)
+    d' = ordEdgesBetween c1 c2 d
+    i  = fromIntegral $ length d'
+    s1 = fromIntegral $ length (ordEdgesBetween c1 c2 d)
+    s2 = fromIntegral $ length (ordEdgesBetween c2 c2 d)
+
+
+bridgeness :: Bridgeness
+           -> [LouvainNode]
+           -> Map (LouvainNodeId, LouvainNodeId) Double
+           -> Map (LouvainNodeId, LouvainNodeId) Double
+bridgeness b ns' ds = fromList . concat . map (\(c1,c2) -> filterEdgesBetween b c1 c2 ds) $ p
+  where
+    p  = catMaybes [ (,) <$> lookup k1 ns <*> lookup k2 ns | k1 <- ks, k2 <- ks, k1 < k2]
+    ns = partition2map ns'
+    ks = keys ns
+
+
+

src/Gargantext/Viz/Graph/Utils.hs

 {-|
-Module      : Gargantext.Graph.Distances.Utils
+Module      : Gargantext.Viz.Graph.Utils
 Description : 
 Copyright   : (c) CNRS, 2017-Present
 License     : AGPL + CECILL v3