Add error clipping to MT demo.

* Compose GRU step naive layer in trainer config helpers.
  * It is uses mixed_layer for gate.
  * It supports ERROR_CLIPPING, DROPOUT
* Add error clipping in MT demo.
* Fix #1143
* Fix #1891

demo/seqToseq/seqToseq_net.py

@@ -69,7 +69,8 @@ def gru_encoder_decoder(data_conf,
                         encoder_size=512,
                         decoder_size=512,
                         beam_size=3,
-                        max_length=250):
+                        max_length=250,
+                        error_clipping=50):
     """
     A wrapper for an attention version of GRU Encoder-Decoder network
     is_generating: whether this config is used for generating
@@ -90,9 +91,19 @@ def gru_encoder_decoder(data_conf,
         input=src_word_id,
         size=word_vector_dim,
         param_attr=ParamAttr(name='_source_language_embedding'))
-    src_forward = simple_gru(input=src_embedding, size=encoder_size)
+    src_forward = simple_gru(
+        input=src_embedding,
+        size=encoder_size,
+        naive=True,
+        gru_layer_attr=ExtraLayerAttribute(
+            error_clipping_threshold=error_clipping))
     src_backward = simple_gru(
-        input=src_embedding, size=encoder_size, reverse=True)
+        input=src_embedding,
+        size=encoder_size,
+        reverse=True,
+        naive=True,
+        gru_layer_attr=ExtraLayerAttribute(
+            error_clipping_threshold=error_clipping))
     encoded_vector = concat_layer(input=[src_forward, src_backward])
 
     with mixed_layer(size=decoder_size) as encoded_proj:
@@ -117,11 +128,13 @@ def gru_encoder_decoder(data_conf,
             decoder_inputs += full_matrix_projection(input=context)
             decoder_inputs += full_matrix_projection(input=current_word)
 
-        gru_step = gru_step_layer(
+        gru_step = gru_step_naive_layer(
             name='gru_decoder',
             input=decoder_inputs,
             output_mem=decoder_mem,
-            size=decoder_size)
+            size=decoder_size,
+            layer_attr=ExtraLayerAttribute(
+                error_clipping_threshold=error_clipping))
 
         with mixed_layer(
                 size=target_dict_dim, bias_attr=True,

demo/seqToseq/translation/train.conf

@@ -28,7 +28,6 @@ train_conf = seq_to_seq_data(data_dir = data_dir,
 
 ### Algorithm Configuration
 settings(
-    learning_method = AdamOptimizer(),
     batch_size = 50,
     learning_rate = 5e-4)
 

python/paddle/trainer_config_helpers/attrs.py

@@ -208,12 +208,15 @@ class ExtraLayerAttribute(object):
                  drop_rate=None,
                  device=None):
         self.attr = dict()
-        if isinstance(error_clipping_threshold, float):
-            assert error_clipping_threshold > 0
-            self.attr["error_clipping_threshold"] = error_clipping_threshold
-
-        if isinstance(drop_rate, float):
-            assert drop_rate > 0
+        if error_clipping_threshold is not None:
+            error_clipping_threshold = float(error_clipping_threshold)
+            if error_clipping_threshold < 0:
+                raise ValueError("Error clipping must > 0")
+            self.attr['error_clipping_threshold'] = error_clipping_threshold
+        if drop_rate is not None:
+            drop_rate = float(drop_rate)
+            if drop_rate < 0:
+                raise ValueError("Dropout rate must > 0")
             self.attr["drop_rate"] = drop_rate
 
         if isinstance(device, int):

python/paddle/trainer_config_helpers/layers.py

@@ -84,6 +84,7 @@ __all__ = [
     'GeneratedInput',
     'SubsequenceInput',
     'gru_step_layer',
+    'gru_step_naive_layer',
     'recurrent_layer',
     'BaseGeneratedInput',
     'conv_operator',
@@ -3084,6 +3085,78 @@ def gru_step_layer(input,
         activation=act)
 
 
+@wrap_bias_attr_default()
+@wrap_param_attr_default()
+@wrap_act_default(param_names=['gate_act'], act=SigmoidActivation())
+@wrap_act_default(act=TanhActivation())
+@wrap_name_default('gru_step')
+@layer_support(ERROR_CLIPPING, DROPOUT)
+def gru_step_naive_layer(input,
+                         output_mem,
+                         size=None,
+                         name=None,
+                         act=None,
+                         gate_act=None,
+                         bias_attr=None,
+                         param_attr=None,
+                         layer_attr=None):
+    """
+    GRU Step Layer, but using MixedLayer to generate. It support ERROR_CLIPPING
+    and DROPOUT.
+
+    :param input:
+    :param output_mem:
+    :param size:
+    :param name:
+    :param act:
+    :param gate_act:
+    :param bias_attr:
+    :param param_attr:
+    :param layer_attr:
+    :return:
+    """
+    if input.size % 3 != 0:
+        raise ValueError("GruStep input size must be divided by 3")
+    if size is None:
+        size = input.size / 3
+
+    def __gate__(gate_name, offset):
+        with mixed_layer(
+                name=name + "_" + gate_name,
+                size=size,
+                layer_attr=layer_attr,
+                bias_attr=bias_attr,
+                act=gate_act) as gate:
+            gate += identity_projection(input=input, offset=offset)
+            gate += full_matrix_projection(
+                input=output_mem, param_attr=param_attr)
+        return gate
+
+    update_gate = __gate__("update", 0)
+    reset_gate = __gate__("reset", size)
+
+    with mixed_layer(
+            name=name + "_reset_output", bias_attr=False) as reset_output:
+        reset_output += dotmul_operator(a=output_mem, b=reset_gate)
+
+    with mixed_layer(
+            name=name + "_output_candidate",
+            size=size,
+            layer_attr=layer_attr,
+            bias_attr=bias_attr,
+            act=act) as output_candidate:
+        output_candidate += identity_projection(input=input, offset=2 * size)
+        output_candidate += full_matrix_projection(
+            input=reset_output, param_attr=param_attr)
+
+    with mixed_layer(name=name) as output:
+        output += identity_projection(output_mem)
+        output += dotmul_operator(a=output_mem, b=update_gate, scale=-1.0)
+        output += dotmul_operator(a=output_candidate, b=update_gate)
+
+    return output
+
+
 @wrap_name_default()
 @layer_support()
 def get_output_layer(input, arg_name, name=None, layer_attr=None):

python/paddle/trainer_config_helpers/networks.py

@@ -825,7 +825,8 @@ def gru_unit(input,
              gru_param_attr=None,
              act=None,
              gate_act=None,
-             gru_layer_attr=None):
+             gru_layer_attr=None,
+             naive=False):
     """
     Define calculations that a gated recurrent unit performs in a single time
     step. This function itself is not a recurrent layer, so that it can not be
@@ -857,7 +858,12 @@ def gru_unit(input,
 
     out_mem = memory(name=name, size=size)
 
-    gru_out = gru_step_layer(
+    if naive:
+        __step__ = gru_step_naive_layer
+    else:
+        __step__ = gru_step_layer
+
+    gru_out = __step__(
         name=name,
         input=input,
         output_mem=out_mem,
@@ -879,7 +885,8 @@ def gru_group(input,
               gru_param_attr=None,
               act=None,
               gate_act=None,
-              gru_layer_attr=None):
+              gru_layer_attr=None,
+              naive=False):
     """
     gru_group is a recurrent layer group version of Gated Recurrent Unit. It
     does exactly the same calculation as the grumemory layer does. A promising
@@ -928,7 +935,8 @@ def gru_group(input,
             gru_param_attr=gru_param_attr,
             act=act,
             gate_act=gate_act,
-            gru_layer_attr=gru_layer_attr)
+            gru_layer_attr=gru_layer_attr,
+            naive=naive)
 
     return recurrent_group(
         name='%s_recurrent_group' % name,
@@ -949,7 +957,8 @@ def simple_gru(input,
                gru_param_attr=None,
                act=None,
                gate_act=None,
-               gru_layer_attr=None):
+               gru_layer_attr=None,
+               naive=False):
     """
     You maybe see gru_step_layer, grumemory in layers.py, gru_unit, gru_group,
     simple_gru in network.py. The reason why there are so many interfaces is
@@ -1018,7 +1027,8 @@ def simple_gru(input,
         gru_param_attr=gru_param_attr,
         act=act,
         gate_act=gate_act,
-        gru_layer_attr=gru_layer_attr)
+        gru_layer_attr=gru_layer_attr,
+        naive=naive)
 
 
 @wrap_name_default('simple_gru2')