src/Gargantext/Core/Viz/Graph/FGL.hs

   1 {-| Module      : Gargantext.Core.Viz.Graph.FGL
   2 Description : FGL main functions used in Garg
   3 Copyright   : (c) CNRS, 2017-Present
   4 License     : AGPL + CECILL v3
   5 Maintainer  : team@gargantext.org
   6 Stability   : experimental
   7 Portability : POSIX
   8
   9 Main FGL funs/types to ease portability with IGraph.
  10
  11 -}
  12
  13 {-# LANGUAGE ConstraintKinds   #-}
  14
  15 module Gargantext.Core.Viz.Graph.FGL where
  16
  17 import Gargantext.Prelude
  18 import qualified Data.Graph.Inductive as FGL
  19 import qualified Data.List as List
  20 ------------------------------------------------------------------
  21 -- | Main Types
  22
  23 type Graph_Undirected = FGL.Gr () ()
  24 type Graph_Directed   = FGL.Gr () ()
  25
  26 type Graph = FGL.Graph
  27 type Node = FGL.Node -- Int
  28 type Edge = FGL.Edge -- (Int, Int)
  29
  30 ------------------------------------------------------------------
  31 -- | Main Functions
  32 mkGraph :: [Node] -> [Edge] -> Graph_Undirected
  33 mkGraph = FGL.mkUGraph
  34
  35 neighbors :: Graph gr => gr a b -> Node -> [Node]
  36 neighbors = FGL.neighbors
  37
  38 -- | TODO bug: if graph is undirected, we need to filter
  39 -- nub . (map (\(n1,n2) -> if n1 < n2 then (n1,n2) else (n2,n1))) . FGL.edges
  40 edges :: Graph gr => gr a b -> [Edge]
  41 edges = FGL.edges
  42
  43 nodes :: Graph gr => gr a b -> [Node]
  44 nodes = FGL.nodes
  45
  46 ------------------------------------------------------------------------
  47 -- | Graph Tools
  48
  49 filterNeighbors :: Graph_Undirected -> Node -> [Node]
  50 filterNeighbors g n = List.nub $ neighbors g n
  51
  52 -- Q: why not D.G.I.deg ? (Int as result)
  53 degree :: Graph_Undirected -> Node -> Double
  54 degree g n = fromIntegral $ List.length (filterNeighbors g n)
  55
  56 vcount :: Graph_Undirected -> Double
  57 vcount = fromIntegral . List.length . List.nub . nodes
  58
  59 -- | TODO tests, optim and use IGraph library, fix IO ?
  60 ecount :: Graph_Undirected -> Double
  61 ecount = fromIntegral . List.length . List.nub . edges
  62
  63
  64 ------------------------------------------------------------------
  65 -- | Main sugared functions
  66 mkGraphUfromEdges :: [(Int, Int)] -> Graph_Undirected
  67 mkGraphUfromEdges es = mkGraph ns es
  68   where
  69     ns = List.nub (a <> b)
  70       where
  71         (a, b) = List.unzip es
  72