simplification done

src/HushGP/GP/Simplification.hs

@@ -1,9 +1,31 @@
 module HushGP.GP.Simplification where
 
+import System.Random.Shuffle
+import System.Random
 import Control.Monad
+import Data.List
 import HushGP.State
 import HushGP.GP.PushArgs
 
+-- | Takes a list of Genes (a plushy), chunks it up into sizes of 1 (type is [[Gene]]).
+-- and a list of indices for replacement (gets sorted before replacement).
+deleteAtMultiple :: [Int] -> [Gene] -> [Gene]
+deleteAtMultiple idxs = deleteAtMultiple' 0 (sort idxs)
+
+-- | Internals of replaceAtMultiple. Takes a chunked plushy and replaces indices
+-- that match the current index as specified at the idx.
+deleteAtMultiple' :: Int -> [Int] -> [Gene] -> [Gene]
+deleteAtMultiple' _ [] plushy = plushy
+deleteAtMultiple' _ _ [] = []
+deleteAtMultiple' curr (idx:idxs) (plushyPiece:plushy) =
+  if curr == idx then deleteAtMultiple' (curr + 1) idxs plushy else plushyPiece : deleteAtMultiple' (curr + 1) (idx:idxs) plushy
+
+-- | Deletes a random amount of genes from the passed plushy based on ant int.
+deleteRandomAmt :: Int -> [Gene] -> IO [Gene]
+deleteRandomAmt k plushy = do
+  randomIndicies <- take k . shuffle' [0..(length plushy - 1)] (length plushy) <$> initStdGen
+  pure $ deleteAtMultiple randomIndicies plushy
+
 -- | Simplifies a Plushy by randomly deleting instructions and seeing how it impacts
 -- performance. Removes genes that have zero to negative performance impact.
 autoSimplifyPlushy :: PushArgs -> [Gene] -> IO [Gene]
@@ -11,9 +33,14 @@ autoSimplifyPlushy pushArgs@PushArgs{simplificationVerbose = simpVerbose, errorF
   when simpVerbose (print ("simplification start plushy length: " <> show (length plushy)))
   autoSimplifyPlushy' pushArgs (eFunc pushArgs tData plushy) 0 plushy
 
+-- | Internals for autosimplification. Keeps track of the amount of steps.
 autoSimplifyPlushy' :: PushArgs -> [Double] -> Int -> [Gene] -> IO [Gene]
-autoSimplifyPlushy' pushArgs@PushArgs{simplificationSteps = simpSteps} initialErrors step plushy
+autoSimplifyPlushy' pushArgs@PushArgs{simplificationVerbose = simpVerbose, simplificationSteps = simpSteps, simplificationMaxAmt = simpK, errorFunction = eFunc, trainingData = tData} initialErrors step plushy
   | step < simpSteps = do
-      newPlushy <- undefined
-      undefined
-  | otherwise = undefined
+      newPlushy <- deleteRandomAmt simpK plushy
+      let newPlushyErrors = eFunc pushArgs tData newPlushy
+      let isBetter = newPlushyErrors <= initialErrors
+      autoSimplifyPlushy' pushArgs initialErrors (succ step) (if isBetter then newPlushy else plushy)
+  | otherwise = do
+      when simpVerbose (print ("simplification end plushy length: " <> show (length plushy)))
+      pure plushy