V2 API recurrent_group 不支持配置双层RNN?

[wanghaoshuang]

I got an err when i run a sequence_nest_rnn demo, which is translated from v1 demo sequence_nest_rnn.conf

my sequence_nest_rnn configuration:

import paddle.v2 as paddle

__all__ = ['nested_sequence_net']

def outer_step(x):
    outer_mem = paddle.layer.memory(name="outer_rnn_state", size=128)
    def inner_step(y):
        inner_mem = paddle.layer.memory(name="inner_rnn_state",
                size=128,
                boot_layer=outer_mem)
        #return resnet.residual_net(ipt=[y, inner_mem], depth=32)
        return paddle.layer.fc(input=[y, inner_mem],
                size=128,
                act=paddle.activation.Relu(),
                name="inner_rnn_state",
                bias_attr=None)
    inner_rnn_output = paddle.layer.recurrent_group(step=inner_step,
            input=x,
            name="inner")
    last = paddle.layer.last_seq(input=inner_rnn_output,
            name="outer_rnn_state")
    return inner_rnn_output

def nested_sequence_net(ipt):
    return paddle.layer.recurrent_group(step=outer_step, input=ipt)

and my data layer:

data = paddle.layer.data("word", paddle.data_type.integer_value_sub_sequence(dict_dim))
emb = paddle.layer.embedding(input=data, size=emb_dim)
net = nested_sequence_net(emb)

and err log:

finish load word_dict, word_dict dim: 5147
I0502 19:05:28.741672 10743 Util.cpp:166] commandline:  --use_gpu=False --trainer_count=1
Traceback (most recent call last):
  File "train.py", line 90, in <module>
    main()
  File "train.py", line 48, in main
    parameters = paddle.parameters.create(cost)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/parameters.py", line 19, in create
    topology = Topology(layers)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/topology.py", line 69, in __init__
    layers, extra_layers=extra_layers)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/layer.py", line 96, in parse_network
    return __parse__(__real_func__)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer_config_helpers/config_parser_utils.py", line 32, in parse_network_config
    config = config_parser.parse_config(network_conf, config_arg_str)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer/config_parser.py", line 3598, in parse_config
    trainer_config()
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/layer.py", line 89, in __real_func__
    real_output = [each.to_proto(context=context) for each in output_layers]
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 109, in to_proto
    context=context)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 109, in to_proto
    context=context)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 109, in to_proto
    context=context)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 112, in to_proto
    self.__parent_layers__[layer_name])
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 111, in <lambda>
    v1_layer = map(lambda x: x.to_proto(context=context),
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 112, in to_proto
    self.__parent_layers__[layer_name])
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 111, in <lambda>
    v1_layer = map(lambda x: x.to_proto(context=context),
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 112, in to_proto
    self.__parent_layers__[layer_name])
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 111, in <lambda>
    v1_layer = map(lambda x: x.to_proto(context=context),
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 100, in to_proto
    p.to_proto(context=context)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/config_base.py", line 116, in to_proto
    ret_val = self.to_proto_impl(**kwargs)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/v2/layer.py", line 197, in to_proto_impl
    return conf_helps.memory(name=self.name, **args)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer_config_helpers/default_decorators.py", line 53, in __wrapper__
    return func(*args, **kwargs)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer_config_helpers/layers.py", line 2929, in memory
    memory_name=memory_name)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer/config_parser.py", line 2338, in Memory
    agent_layer = AgentLayer(agent_name, size)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer/config_parser.py", line 2244, in __init__
    name, 'agent', size, inputs=[], device=device)
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer/config_parser.py", line 1441, in __init__
    height = self.get_input_layer(0).height
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/paddle/trainer/config_parser.py", line 1447, in get_input_layer
    return g_layer_map[self.config.inputs[input_index].input_layer_name]
  File "/home/work/wanghaoshuang/workspace/paddle_dev/env/idl/paddle/output/python27-gcc482/lib/python2.7/site-packages/google/protobuf/internal/containers.py", line 204, in __getitem__
    return self._values[key]
IndexError: list index out of range

在V1中，nested rnn的input需要用SubsequenceInput标记，但是在V2的recurrent_group里没有涉及SubsequenceInput的逻辑，而且没有处理subsequence的逻辑，是不是V2的recurrent_group暂不支持双层RNN?

[lcy-seso]

This problem has been fixed by this PR #2288.

Thank you for the issue.