implement mutateGenomeAddGene

1 files changed, 28 insertions, 3 deletions

diff --git a/src/Genome.hs b/src/Genome.hs
index 500512c..927005e 100644
--- a/src/Genome.hs
+++ b/src/Genome.hs
@@ -8,6 +8,7 @@ module Genome
 
   , mutateGenomeAddInternal
   , mutateGenomeRemoveInternal
+  , mutateGenomeAddGene 
   ) where
 
 
@@ -111,8 +112,6 @@ validn g (Output x)
   | (inRange (0, numOutput g - 1) x) = Output x
   | otherwise = error "out of range Output!"
 
-
-
 incrementNeuron :: Genome -> NeuronIndex -> NeuronIndex
 incrementNeuron g (Input x)
   | (x >= numInput g - 1) = validn g (Internal 0)
@@ -124,7 +123,6 @@ incrementNeuron g (Output x)
   | (x >= numOutput g - 1) = error "cannot increment past the end of outputs!"
   | otherwise = validn g (Output $ x+1)
 
-
 decrementNeuron :: Genome -> NeuronIndex -> NeuronIndex
 decrementNeuron g (Input x)
   | (x <= 0) = error "cannot decrement past the first Input!"
@@ -139,3 +137,30 @@ decrementNeuron g (Output x)
 isInternal :: NeuronIndex -> Bool
 isInternal (Internal _) = True
 isInternal _ = False
+
+
+-- add a new, random gene
+mutateGenomeAddGene :: RandomGen a => Genome -> a -> (Genome, a)
+mutateGenomeAddGene g r =
+  let
+    (so, r') = randomSource g r
+    (si, r'') = randomSink g r'
+    (w, r''') = randomR (-4, 4) r''
+    gene = Gene so si w
+  in (g {genes = gene:(genes g)}, r''')
+
+    
+
+randomSource :: RandomGen a => Genome -> a -> (NeuronIndex, a)
+randomSource g r =
+  let
+    (idx, r') = randomR (0, numInput g + numInternal g - 1) r
+    result = if idx < numInput g then Input idx else Internal $ idx - numInput g
+  in (result, r')
+
+randomSink :: RandomGen a => Genome -> a -> (NeuronIndex, a)
+randomSink g r =
+  let
+    (idx, r') = randomR (0, numInternal g + numOutput g - 1) r
+    result = if idx < numInternal g then Internal idx else Output $ idx - numInput g
+  in (result, r')