Add the updateAll function add the Barnes-Hut threshold parameter

app/Main.hs

@@ -64,22 +64,24 @@ csvFromBodies dt bs = concat $ map (csvFromBody dt) bs
 
 -- | Compute all the steps of the simulation
 steps :: Double -- ^ The time step
+  -> Double -- ^ The Barnes-Hut threshold theta
   -> [Body] -- ^ The initial state (list of bodies)
   -> [(Double, [Body])] -- ^ List of successive states with the
                         -- corresponding time
-steps dt b = zip (iterate (dt +) 0) (iterate (updateAll dt) b)
+steps dt theta b = zip (iterate (dt +) 0) (iterate (updateAll dt theta) b)
 
 -- | Show all the steps as CSV
 csvFromInit :: Int -- ^ The number of time steps to keep
   -> Double -- ^ The time step
+  -> Double -- ^ The Barnes-Hut threshold theta
   -> [Body] -- ^ The initial state (list of bodies)
   -> String -- ^ CSV data
-csvFromInit n dt b = concat . take n $ map (uncurry csvFromBodies) (steps dt b)
+csvFromInit n dt theta b = concat . take n $ map (uncurry csvFromBodies) (steps dt theta b)
 
 main :: IO ()
 main = do
   bodies <- replicateM 100 randomBody
-  putStrLn $ csvFromInit 100000 60 bodies
+  putStrLn $ csvFromInit 100000 60 0.5 bodies
 
 {-
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src/Lib.hs

@@ -28,6 +28,7 @@ module Lib (
   acceleration,
   -- * Simulation
   update,
+  updateAll,
   -- * Examples
   au, sun, earth, moon, mercury, venus, mars
   ) where
@@ -246,6 +247,18 @@ update dt theta tree (Body name r m pos speed) =
         newpos = pos + dt *^ P newspeed
 
 
+-- | Update all Bodies with a time step dt and a Barnes-Hut threshold
+-- theta
+updateAll :: Double -- ^ The time step
+  -> Double -- ^ The Barnes-Hut threshold theta
+  -> [Body] -- ^ A list of Bodies
+  -> [Body] -- ^ The updated list of Bodies
+updateAll dt theta bs =
+  map (update dt theta tree) bs
+  where tree = buildTree bs
+
+
+
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 -- EXAMPLES
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