[graph explorer] normalize nodes before making a snapshot

src/Gargantext/Components/GraphExplorer/Button.purs

@@ -89,7 +89,7 @@ cameraButton { id
         edges <- Sigmax.getEdges s
         nodes <- Sigmax.getNodes s
         let graphData = GET.GraphData $ hyperdataGraph { edges = map GEU.stEdgeToGET edges
-                                                       , nodes = map GEU.stNodeToGET nodes }
+                                                       , nodes = GEU.normalizeNodes $ map GEU.stNodeToGET nodes }
         let cameras = map Sigma.toCamera $ Sigma.cameras s
         let camera = case cameras of
               [c] -> GET.Camera { ratio: c.ratio

src/Gargantext/Components/GraphExplorer/Utils.purs

-module Gargantext.Components.GraphExplorer.Utils
-where
+module Gargantext.Components.GraphExplorer.Utils where
+
+import Data.Maybe (Maybe(..))
 
 import Gargantext.Prelude
 
 import Gargantext.Components.GraphExplorer.Types as GET
 import Gargantext.Hooks.Sigmax.Types as ST
+import Gargantext.Utils.Array as GUA
 
 
 stEdgeToGET :: Record ST.Edge -> GET.Edge
@@ -20,3 +22,29 @@ stNodeToGET { id, label, x, y, _original: GET.Node { attributes, size, type_ } }
   , x
   , y
   }
+
+normalizeNodes :: Array GET.Node -> Array GET.Node
+normalizeNodes ns = map normalizeNode ns
+  where
+    xs = map (\(GET.Node { x }) -> x) ns
+    ys = map (\(GET.Node { y }) -> y) ns
+    mMinx = GUA.min xs
+    mMaxx = GUA.max xs
+    mMiny = GUA.min ys
+    mMaxy = GUA.max ys
+    mXrange = do
+      minx <- mMinx
+      maxx <- mMaxx
+      pure $ maxx - minx
+    mYrange = do
+      miny <- mMiny
+      maxy <- mMaxy
+      pure $ maxy - miny
+    xdivisor = case mXrange of
+      Nothing -> 1.0
+      Just xdiv -> 1.0 / xdiv
+    ydivisor = case mYrange of
+      Nothing -> 1.0
+      Just ydiv -> 1.0 / ydiv
+    normalizeNode (GET.Node n@{ x, y }) = GET.Node $ n { x = x * xdivisor
+                                                       , y = y * ydivisor }

src/Gargantext/Utils/Array.purs

-module Gargantext.Utils.Array (push) where
+module Gargantext.Utils.Array (max, min, push) where
 
+import Data.Array as A
+import Data.Foldable (foldr)
+import Data.Maybe (Maybe(..))
+import Data.Ord as Ord
 import Effect (Effect)
-import Data.Unit (Unit)
 import Effect.Uncurried (EffectFn2, runEffectFn2)
 
+import Gargantext.Prelude
+
 foreign import _push :: forall a. EffectFn2 (Array a) a Unit
 
 push :: forall a. Array a -> a -> Effect Unit
 push = runEffectFn2 _push
+
+
+max :: forall a. Ord a => Array a -> Maybe a
+max xs = foldr reducer (A.head xs) xs
+  where
+    reducer _ Nothing = Nothing
+    reducer v (Just acc) = Just $ Ord.max acc v
+
+min :: forall a. Ord a => Array a -> Maybe a
+min xs = foldr reducer (A.head xs) xs
+  where
+    reducer _ Nothing = Nothing
+    reducer v (Just acc) = Just $ Ord.min acc v