better fitness

src/Environment.hs

@@ -151,7 +151,15 @@ fitness p = do
   products <- produceCompounds p nutrients -- produce compounds
   survivalRate <- deterPredators products  -- defeat predators with produced compounds
   let sumEnzymes = sum $ (\(_,q,a) -> fromIntegral q*a) <$> genome p -- amount of enzymes * activation = resources "wasted"
-      costOfEnzymes = 0.99 ** sumEnzymes
+      staticCostOfEnzymes = 1 - 0.01*sumEnzymes -- static cost of creating enzymes
+      -- primaryEnzymes = filter (\(e,_,_) -> case (fst.fst.synthesis) e of -- select enzymes which use substrate
+      --                                        Substrate _ -> True
+      --                                        otherwise   -> False)
+      --                         (genome p)
+  nutrientsAvailable <- fmap snd <$> asks soil
+  let nutrientsLeft = [products ! i | i <- [0..fromEnum (maxBound :: Nutrient)]]
+      nutrientRatio = minimum $ zipWith (/) nutrientsLeft nutrientsAvailable
+      costOfEnzymes = max 0 $ staticCostOfEnzymes - nutrientRatio * 0.1 -- cost to keep enzymes are static costs + amount of nutrient sucked out of the primary cycle
   return $ survivalRate * costOfEnzymes
   -- can also be written as, but above is more clear.
   -- fitness p = absorbNutrients p >>= produceCompounds p >>= deterPredators
@@ -174,16 +182,22 @@ produceCompounds (Plant genes _) substrate = do
   return final
 
 
+-- TODO:
+-- - choose predators beforehand, then only apply those who appear in full force.
+-- - dampen full-force due to auto-mimicry-effect. => Fitness would not depend on single plant.
 deterPredators :: Vector Amount -> World Probability
 deterPredators cs = do
   ps <- asks predators
   ts <- asks toxicCompounds
+  ds <- liftIO $ randoms <$> newStdGen
   let
+     appearingPredators = fmap fst . filter (\((_,p),r) -> p > r) $ zip ps ds -- assign one probability to each predator, filter those who appear, throw random data away again.
+                                                                              -- appearingPredators is now a sublist of ps.
      deter :: Predator -> Double
          -- multiply   (toxicity of t with 100% effectiveness at l| for all toxins t | and t not in p's irresistance-list)
      deter p = product [1 - min 1 (cs ! fromEnum t / l)           | (t,l) <- ts,       t `elem` irresistance p]
          -- multiply  (probability of occurence * intensity of destruction / probability to deter predator | for all predators)
-  return $ product ([min 1 ((1-prob) * fitnessImpact p / deter p) | (p,prob) <- ps] `using` parList rdeepseq)
+  return $ product ([min 1 ((1-prob) * fitnessImpact p / deter p) | (p,prob) <- appearingPredators])
 
 -- Mating & Creation of diversity
 -- ------------------------------