bugfix in char-rnn example (fix #323)

examples/Char-RNN/char-rnn.py

@@ -49,8 +49,8 @@ class CharRNNData(RNGDataFlow):
         print(sorted(self.chars))
         self.vocab_size = len(self.chars)
         param.vocab_size = self.vocab_size
-        char2idx = {c: i for i, c in enumerate(self.chars)}
-        self.whole_seq = np.array([char2idx[c] for c in data], dtype='int32')
+        self.char2idx = {c: i for i, c in enumerate(self.chars)}
+        self.whole_seq = np.array([self.char2idx[c] for c in data], dtype='int32')
         logger.info("Corpus loaded. Vocab size: {}".format(self.vocab_size))
 
     def size(self):
@@ -146,7 +146,7 @@ def sample(path, start, length):
     # feed the starting sentence
     initial = np.zeros((1, param.rnn_size))
     for c in start[:-1]:
-        x = np.array([[ds.lut.get_idx(c)]], dtype='int32')
+        x = np.array([[ds.char2idx[c]]], dtype='int32')
         _, state = pred(x, initial, initial, initial, initial)
 
     def pick(prob):
@@ -158,9 +158,9 @@ def sample(path, start, length):
     ret = start
     c = start[-1]
     for k in range(length):
-        x = np.array([[ds.lut.get_idx(c)]], dtype='int32')
+        x = np.array([[ds.char2idx[c]]], dtype='int32')
         prob, state = pred(x, state[0, 0], state[0, 1], state[1, 0], state[1, 1])
-        c = ds.lut.get_obj(pick(prob[0]))
+        c = ds.chars[pick(prob[0])]
         ret += c
     print(ret)