Fix sample_beam in CaptionModel.

Author: ruotianluo

models/CaptionModel.py

@@ -95,7 +95,7 @@ def sample_beam(self, fc_feats, att_feats, opt={}):
 
         self.done_beams = [[] for _ in range(batch_size)]
         for k in range(batch_size):
-            state = self.init_hidden(fc_feats[k:k+1].expand(beam_size, self.rnn_size))
+            state = self.init_hidden(fc_feats[k:k+1]).expand(beam_size, self.rnn_size)
             tmp_fc_feats = fc_feats[k:k+1].expand(beam_size, self.fc_feat_size)
             tmp_att_feats = att_feats[k:k+1].expand(*((beam_size,)+att_feats.size()[1:]))