[temp] tried out to fix algorithm, according to the python code

README.md

@@ -12,3 +12,10 @@ git clone ssh://git@gitlab.iscpif.fr:20022/gargantext/clustering-louvain-cpluspl
 cd clustering-louvain-cplusplus
 ./install
 ```
+
+## Running
+
+``` bash
+stack --nix build --profile
+stack exec --profile -- run-example +RTS -xc
+```

clustering-louvain.cabal

@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: d5768235cb674d3617c860c0be6df203e51373bd36995a8e7df1f612778cdeee
+-- hash: e7eca8a6c90593bd7b67a5ba8bc4ece3253f1ff4f46353aa6aa75dbc4b6ee829
 
 name:           clustering-louvain
 version:        0.1.0.0

src/Data/Graph/Clustering/Example.hs

@@ -19,7 +19,7 @@ import Data.Graph.Clustering.FLouvain
 -- Example call:
 -- putStrLn $ prettify $ iterateOnce cuiller
 -- Prelude.map (fst3 . unCommunity . snd) $ labNodes $ iterateOnce karate
-iterateOnce :: Show a => Gr a Double -> CGr a
+iterateOnce :: (Show a, Eq a) => Gr a Double -> CGr a
 iterateOnce gr = iteration fgr cgr
   where
     fgr = toFGraph    gr
@@ -38,10 +38,10 @@ runFLouvain cycles n fgr = do
   putStrLn (show fgrNext :: Text)
   runFLouvain (cycles - 1) n fgrNext
 
-runIterations :: Show a => Int -> Gr a Double -> IO (CGr a)
+runIterations :: (Show a, Eq a) => Int -> Gr a Double -> IO (CGr a)
 runIterations n gr = runFIterations n $ toFGraph gr
 
-runFIterations :: Show a => Int -> FGraph a () -> IO (CGr a)
+runFIterations :: (Show a, Eq a) => Int -> FGraph a () -> IO (CGr a)
 runFIterations n fgr = do
   let fgrWeight = graphWeight fgr
   let initCgr   = initialCGr fgr
@@ -70,7 +70,7 @@ runFIterations n fgr = do
       putStrLn $ T.unpack $ show $ modularity fgr iterNextCgr fgrWeight
       return iterNextCgr
 
-runLouvainFirstStepIterate :: Show a => Int -> Gr a Double -> (Modularity, CGr a)
+runLouvainFirstStepIterate :: (Show a, Eq a) => Int -> Gr a Double -> (Modularity, CGr a)
 runLouvainFirstStepIterate n gr = (modularity fgr cgr m, cgr)
   where
     fgr = toFGraph gr

src/Data/Graph/Clustering/FLouvain.hs

@@ -32,6 +32,8 @@ doi:10.1088/1742-5468/2008/10/P10008.
 
 -}
 
+-- TODO Try modularity instead of delta in the step function
+
 module Data.Graph.Clustering.FLouvain
   where
 
@@ -46,12 +48,13 @@ import Data.Graph.Clustering.Louvain.Types
 ------------------------------------------------------------------------
 
 -- | Main Louvain first step iteration function
-louvainFirstStepIterate :: Int -> FGraph a b -> CGr a
+louvainFirstStepIterate :: (Show a, Eq a) => Int -> FGraph a b -> CGr a
 louvainFirstStepIterate n gr = fixPt n iterator cond initCGr
   where
     initCGr      = initialCGr  gr
     grWeight     = graphWeight gr
     iterator cgr = iteration   gr cgr
+    -- modularity in [-1, 1]
     cond cgr     = (unModularity $ modularity gr cgr grWeight) < 0.1
 
 -- | Second step from the Louvain paper -- given a clustering, create new graph
@@ -60,10 +63,11 @@ louvainSecondStep :: forall a b c. Eq c => FGraph a b -> CGr c -> FGraph (Commun
 louvainSecondStep gr cgr = mkFGraph nodes edges
   where
     nodes :: [LNode (Community c)]
-    --nodes = filter (\(_, com) -> length (comNodes com) > 0) $ labNodes cgr
-    nodes = labNodes cgr
+    nodes = filter (\(_, com) -> length (comNodes com) > 0) $ labNodes cgr
+    --nodes = labNodes cgr
     edges :: [(Node, Node, Double)]
-    edges = concatMap comEdges nodes
+    --edges = concatMap comEdges nodes
+    edges = filter (\(_, _, w) -> w > 0.0) $ concatMap comEdges nodes
     comEdges :: LNode (Community c) -> [(Node, Node, Double)]
     comEdges lnCom = mapMaybe (comToComEdge lnCom) nodes
     comToComEdge :: LNode (Community c) -> LNode (Community c) -> Maybe (Node, Node, Double)
@@ -121,26 +125,34 @@ modularity gr cgr m = Modularity $ coeff * ( ufold modularity' 0.0 cgr )
     modularity' (_, _, com, _) acc = acc + component
       where
         component = (unInWeightSum $ comInWeightSum com) - weightsMul
-        weightsMul = coeff * ( sum $ map weightsMul' $ comNodes com )
-        weightsMul' n = (ki n) * (sum $ map ki $ comNodes com)
+        weightsMul = coeff * (unTotWeightSum $ comTotWeightSum com) * (unTotWeightSum $ comTotWeightSum com)
+        --weightsMul = coeff * ( sum $ map weightsMul' $ comNodes com )
+        --weightsMul' n = (ki n) * (sum $ map ki $ comNodes com)
         -- k_i variable in formula (1)
-        ki :: Node -> Double
-        ki n = unNodeWeightSum $ nodeWeightSum $ context gr n
+        -- ki :: Node -> Double
+        -- ki n = unNodeWeightSum $ nodeWeightSum $ context gr n
 
 type Delta c = Community c -> NodeWeightSum -> NodeComWeightSum -> GraphWeightSum -> DeltaQ
 -- | Delta Q function from Louvain paper (2).
 delta :: Delta c
-delta com ki kiin m = DeltaQ $ acc - dec
+-- delta com ki kiin m = DeltaQ $ acc - dec
+--   where
+--     inWeightSum = comInWeightSum com
+--     totWeightSum = comTotWeightSum com
+--     acc = accL - accR * accR
+--     accL = 0.5 * (unInWeightSum inWeightSum + 2.0 * (unNodeComWeightSum kiin)) / (unGraphWeightSum m)
+--     accR = 0.5 * (unTotWeightSum totWeightSum + unNodeWeightSum ki) / (unGraphWeightSum m)
+--     dec = decL - decM * decM - decR * decR
+--     decL = 0.5 * (unInWeightSum inWeightSum) / (unGraphWeightSum m)
+--     decM = 0.5 * (unTotWeightSum totWeightSum) / (unGraphWeightSum m)
+--     decR = 0.5 * (unNodeWeightSum ki) / (unGraphWeightSum m)
+delta com ki kiin m = DeltaQ $ 2.0 * kiin' - totWeightSum * ki' / m'
   where
-    inWeightSum = comInWeightSum com
-    totWeightSum = comTotWeightSum com
-    acc = accL - accR * accR
-    accL = 0.5 * (unInWeightSum inWeightSum + 2.0 * (unNodeComWeightSum kiin)) / (unGraphWeightSum m)
-    accR = 0.5 * (unTotWeightSum totWeightSum + unNodeWeightSum ki) / (unGraphWeightSum m)
-    dec = decL - decM * decM - decR * decR
-    decL = 0.5 * (unInWeightSum inWeightSum) / (unGraphWeightSum m)
-    decM = 0.5 * (unTotWeightSum totWeightSum) / (unGraphWeightSum m)
-    decR = 0.5 * (unNodeWeightSum ki) / (unGraphWeightSum m)
+    totWeightSum = unTotWeightSum $ comTotWeightSum com
+    kiin' = unNodeComWeightSum kiin
+    ki' = unNodeWeightSum ki
+    m' = unGraphWeightSum m
+
 
 -- | One iteration step takes the graph and existing communities as a graph and
 -- computes new community graph
@@ -151,7 +163,7 @@ delta com ki kiin m = DeltaQ $ acc - dec
 -- 'step . context gr . node''
 -- We could avoid the higher complexity, eg. by precomputing the whole graph
 -- into a HashMap Node [Edge].
-iteration :: FGraph a b -> CGr c -> CGr c
+iteration :: (Show c, Eq c) => FGraph a b -> CGr c -> CGr c
 iteration gr cs = xdfsFoldWith suc' (\(_, v, _, _)
                 -> step gw $ context gr $ v) cs (nodes gr) gr
   where
@@ -162,25 +174,36 @@ iteration gr cs = xdfsFoldWith suc' (\(_, v, _, _)
 -- TODO Remember to filter out empty Communities
 -- | Step for one node. We try re-assign it to a neighbouring community, where
 -- the increase of modularity for graph will be the largest
-step :: forall a b c. GraphWeightSum -> CFunFold a (FEdge b) (CGr c)
-step gw ctx@(_, v, _, _) cgr = newCgr
+step :: forall a b c. (Show c, Eq c) => GraphWeightSum -> CFunFold a (FEdge b) (CGr c)
+step gw ctx@(_, v, _, _) cgr = trace ("step v: " <> show v :: Text) $ newCgr
   where
+    stepStr = "[step, node: " <> show v <> "]"
+   
     newCgr = case mNc of
       Nothing -> cgr
       Just nc ->
-        if bestFitdq > 0.0 then
-          let newBestFitCom = makeMove Into bestFitCom
-              newNc = makeMove OutOf nc
-              in
-            replaceLNode (replaceLNode cgr newNc) newBestFitCom
-        else
-          cgr
+        case ncs of
+          [] -> cgr
+          _  ->
+            let (DeltaQ deltaCurrent) = delta' nc
+            in
+            if bestFitdq > 0.0 && bestFitdq > deltaCurrent then
+              let newBestFitCom = makeMove Into bestFitCom
+                  newNc = makeMove OutOf nc
+                  cgrWithNewNc = replaceLNode cgr newNc
+                  replaced = replaceLNode cgrWithNewNc newBestFitCom
+                  in
+              trace (stepStr <> " replaced: " <> show replaced <> "\n" <>
+                     stepStr <> " deltaCurrent: " <> show deltaCurrent :: Text) $ replaced
+            else
+              cgr
 
     (bestFitCom, DeltaQ bestFitdq) =
+      trace (stepStr <> " bestFit, deltas: " <> show (map (\((n, _), d) -> "Com: " <> show n <> ", delta: " <> show d :: Text) deltas) :: Text) $
       maximumBy (\(_, deltaq1) (_, deltaq2) -> compare deltaq1 deltaq2) deltas
 
     mNc :: Maybe (LNode (Community c))
-    mNc = nodeCommunity v cgr
+    mNc = nodeCommunity v cgr   
     ncs :: [LNode (Community c)]
     ncs = nodeNeighbours v cgr
 
@@ -202,12 +225,18 @@ step gw ctx@(_, v, _, _) cgr = newCgr
     deltas = map (\c -> (c, delta' c)) ncs
 
     delta' :: LNode (Community c) -> DeltaQ
-    delta' com = delta (llab com) ki kiin gw
+    delta' com = trace (stepStr <> " com: " <> show com <>
+                                   ", ki: " <> show ki <>
+                                   ", kiin: " <> show kiin <>
+                                   ", gw: " <> show gw <>
+                                   ", delta: " <> show d) d
       where
         -- k_i,in variable in formula (2)
         kiin :: NodeComWeightSum
         kiin = nodeComWeightSum (llab com) ctx
 
+        d = delta (llab com) ki kiin gw
+
     -- TODO Compute \Delta Q (gain of moving node v into Community C) which consists of:
     -- - Community InWeightSum
     -- - Community TotWeightSum
@@ -231,11 +260,11 @@ nodeCommunity n cgr = head (filter f $ labNodes cgr)
     f (_, com) = n `elem` comNodes com
 
 -- | Find 'LNode's of 'Community' graph neighbouring a given node
-nodeNeighbours :: Node -> CGr c -> [LNode (Community c)]
+nodeNeighbours :: Eq c => Node -> CGr c -> [LNode (Community c)]
 nodeNeighbours n cgr =
   case nodeCommunity n cgr of
     Nothing        -> []
-    Just (cn, _)   -> mapMaybe (lnode cgr) (neighbors cgr cn)
+    Just (cn, _)   -> DL.nub $ mapMaybe (lnode cgr) (neighbors cgr cn)
 
 -- | Find 'Ajd CGrEdge's of 'Community' graph neighbouring a given node
 -- nodeLNeighbours :: Node -> CGr -> Adj CGrEdge
@@ -262,15 +291,20 @@ moveNodeWithContext ctx@(_, n, _, _) direction com@(Community (ns, inwsum, totws
 
       (newInWsum, newTotWsum) =
         case direction of
-          Into  -> (unInWeightSum inwsum + unNodeComWeightSum cws, unTotWeightSum totwsum - unNodeComWeightSum cws + unNodeNonComWeightSum nws)
-          OutOf -> (unInWeightSum inwsum - unNodeComWeightSum cws, unTotWeightSum totwsum + unNodeComWeightSum cws - unNodeNonComWeightSum nws)
+          --Into  -> (unInWeightSum inwsum + unNodeComWeightSum cws, unTotWeightSum totwsum - unNodeComWeightSum cws + unNodeNonComWeightSum nws)
+          --OutOf -> (unInWeightSum inwsum - unNodeComWeightSum cws, unTotWeightSum totwsum + unNodeComWeightSum cws - unNodeNonComWeightSum nws)
+          Into  -> (unInWeightSum inwsum + unNodeComWeightSum cws, unTotWeightSum totwsum + unNodeWeightSum nws)
+          OutOf -> (unInWeightSum inwsum - unNodeComWeightSum cws, unTotWeightSum totwsum - unNodeWeightSum nws)
+
+      nws :: NodeWeightSum
+      nws = nodeWeightSum ctx
 
       -- sum of edge weights inside community
       cws :: NodeComWeightSum
       cws = nodeComWeightSum com ctx
 
-      nws :: NodeNonComWeightSum
-      nws = nodeNonComWeightSum com ctx
+      -- nws :: NodeNonComWeightSum
+      -- nws = nodeNonComWeightSum com ctx
 
 
 {-

stack.yaml

@@ -20,6 +20,11 @@
 # resolver: https://example.com/snapshots/2018-01-01.yaml
 resolver: lts-14.27
 
+nix:
+  enable: true
+  add-gc-roots: true
+  shell-file: build-shell.nix
+
 # User packages to be built.
 # Various formats can be used as shown in the example below.
 #