Make each feature set provide initial PSQT values for each feature.

feature_set.py

@@ -101,4 +101,10 @@ def get_virtual_to_real_features_gather_indices(self):
                 indices.append([offset + i for i in i_fact])
             real_offset += feature.num_real_features
             offset += feature.num_features
-        return indices
+        return indices
+
+    def get_initial_psqt_features(self):
+        init = []
+        for feature in self.features:
+            init += feature.get_initial_psqt_features()
+        return init

halfka.py

@@ -15,6 +15,28 @@ def halfka_idx(is_white_pov: bool, king_sq: int, sq: int, p: chess.Piece):
   p_idx = (p.piece_type - 1) * 2 + (p.color != is_white_pov)
   return 1 + orient(is_white_pov, sq) + p_idx * NUM_SQ + king_sq * NUM_PLANES
 
+def halfka_psqts():
+  # values copied from stockfish, in stockfish internal units
+  piece_values = {
+    chess.PAWN : 126,
+    chess.KNIGHT : 781,
+    chess.BISHOP : 825,
+    chess.ROOK : 1276,
+    chess.QUEEN : 2538
+  }
+
+  values = [0] * (NUM_PLANES * NUM_SQ)
+
+  for ksq in range(64):
+    for s in range(64):
+      for pt, val in piece_values.items():
+        idxw = halfka_idx(True, ksq, s, chess.Piece(pt, chess.WHITE))
+        idxb = halfka_idx(True, ksq, s, chess.Piece(pt, chess.BLACK))
+        values[idxw] = val
+        values[idxb] = -val
+
+  return values
+
 class Features(FeatureBlock):
   def __init__(self):
     super(Features, self).__init__('HalfKA', 0x5f134cb8, OrderedDict([('HalfKA', NUM_PLANES * NUM_SQ)]))
@@ -27,6 +49,9 @@ def piece_features(turn):
       return indices
     return (piece_features(chess.WHITE), piece_features(chess.BLACK))
 
+  def get_initial_psqt_features(self):
+    return halfka_psqts()
+
 class FactorizedFeatures(FeatureBlock):
   def __init__(self):
     super(FactorizedFeatures, self).__init__('HalfKA^', 0x5f134cb8, OrderedDict([('HalfKA', NUM_PLANES * NUM_SQ), ('A', NUM_SQ * NUM_PT)]))
@@ -42,6 +67,9 @@ def get_feature_factors(self, idx):
 
     return [idx, self.get_factor_base_feature('A') + a_idx]
 
+  def get_initial_psqt_features(self):
+    return halfka_psqts() + [0] * (NUM_SQ * NUM_PT)
+
 '''
 This is used by the features module for discovery of feature blocks.
 '''

halfkp.py

@@ -29,6 +29,9 @@ def piece_features(turn):
       return indices
     return (piece_features(chess.WHITE), piece_features(chess.BLACK))
 
+  def get_initial_psqt_features(self):
+    raise Exception('Not supported yet. See HalfKA')
+
 class FactorizedFeatures(FeatureBlock):
   def __init__(self):
     super(FactorizedFeatures, self).__init__('HalfKP^', 0x5d69d5b8, OrderedDict([('HalfKP', NUM_PLANES * NUM_SQ), ('HalfK', NUM_SQ), ('P', NUM_SQ * 10 )]))
@@ -60,6 +63,9 @@ def get_feature_factors(self, idx):
 
     return [idx, self.get_factor_base_feature('HalfK') + k_idx, self.get_factor_base_feature('P') + p_idx]
 
+  def get_initial_psqt_features(self):
+    raise Exception('Not supported yet. See HalfKA^')
+
 '''
 This is used by the features module for discovery of feature blocks.
 '''