Source code for deepctr.models.onn

# -*- coding:utf-8 -*-
"""
Author:
    Weichen Shen, weichenswc@163.com

Reference:
    [1] Yang Y, Xu B, Shen F, et al. Operation-aware Neural Networks for User Response Prediction[J]. arXiv preprint arXiv:1904.12579, 2019. (https://arxiv.org/pdf/1904.12579)


"""

import itertools

from tensorflow.python.keras import backend as K
from tensorflow.python.keras.layers import (Dense, Embedding, Lambda,
                                            multiply, Flatten)
try:
    from tensorflow.python.keras.layers import BatchNormalization
except ImportError:
    import tensorflow as tf
    BatchNormalization = tf.keras.layers.BatchNormalization
from tensorflow.python.keras.models import Model
from tensorflow.python.keras.regularizers import l2

from ..feature_column import SparseFeat, VarLenSparseFeat, build_input_features, get_linear_logit
from ..inputs import get_dense_input
from ..layers.core import DNN, PredictionLayer
from ..layers.sequence import SequencePoolingLayer
from ..layers.utils import concat_func, Hash, NoMask, add_func, combined_dnn_input


[docs]def ONN(linear_feature_columns, dnn_feature_columns, dnn_hidden_units=(256, 128, 64), l2_reg_embedding=1e-5, l2_reg_linear=1e-5, l2_reg_dnn=0, dnn_dropout=0, seed=1024, use_bn=True, reduce_sum=False, task='binary', ): """Instantiates the Operation-aware Neural Networks architecture. :param linear_feature_columns: An iterable containing all the features used by linear part of the model. :param dnn_feature_columns: An iterable containing all the features used by deep part of the model. :param dnn_hidden_units: list,list of positive integer or empty list, the layer number and units in each layer of deep net :param l2_reg_embedding: float. L2 regularizer strength applied to embedding vector :param l2_reg_linear: float. L2 regularizer strength applied to linear part. :param l2_reg_dnn: float . L2 regularizer strength applied to DNN :param seed: integer ,to use as random seed. :param dnn_dropout: float in [0,1), the probability we will drop out a given DNN coordinate. :param use_bn: bool,whether use bn after ffm out or not :param reduce_sum: bool,whether apply reduce_sum on cross vector :param task: str, ``"binary"`` for binary logloss or ``"regression"`` for regression loss :return: A Keras model instance. """ features = build_input_features(linear_feature_columns + dnn_feature_columns) inputs_list = list(features.values()) linear_logit = get_linear_logit(features, linear_feature_columns, seed=seed, prefix='linear', l2_reg=l2_reg_linear) sparse_feature_columns = list( filter(lambda x: isinstance(x, SparseFeat), dnn_feature_columns)) if dnn_feature_columns else [] varlen_sparse_feature_columns = list( filter(lambda x: isinstance(x, VarLenSparseFeat), dnn_feature_columns)) if dnn_feature_columns else [] sparse_embedding = {fc_j.embedding_name: {fc_i.embedding_name: Embedding(fc_j.vocabulary_size, fc_j.embedding_dim, embeddings_initializer=fc_j.embeddings_initializer, embeddings_regularizer=l2( l2_reg_embedding), mask_zero=isinstance(fc_j, VarLenSparseFeat), name='sparse_emb_' + str( fc_j.embedding_name) + '_' + fc_i.embedding_name) for fc_i in sparse_feature_columns + varlen_sparse_feature_columns} for fc_j in sparse_feature_columns + varlen_sparse_feature_columns} dense_value_list = get_dense_input(features, dnn_feature_columns) embed_list = [] for fc_i, fc_j in itertools.combinations(sparse_feature_columns + varlen_sparse_feature_columns, 2): i_input = features[fc_i.name] if fc_i.use_hash: i_input = Hash(fc_i.vocabulary_size)(i_input) j_input = features[fc_j.name] if fc_j.use_hash: j_input = Hash(fc_j.vocabulary_size)(j_input) fc_i_embedding = feature_embedding(fc_i, fc_j, sparse_embedding, i_input) fc_j_embedding = feature_embedding(fc_j, fc_i, sparse_embedding, j_input) element_wise_prod = multiply([fc_i_embedding, fc_j_embedding]) if reduce_sum: element_wise_prod = Lambda(lambda element_wise_prod: K.sum( element_wise_prod, axis=-1))(element_wise_prod) embed_list.append(element_wise_prod) ffm_out = Flatten()(concat_func(embed_list, axis=1)) if use_bn: ffm_out = BatchNormalization()(ffm_out) dnn_input = combined_dnn_input([ffm_out], dense_value_list) dnn_out = DNN(dnn_hidden_units, l2_reg=l2_reg_dnn, dropout_rate=dnn_dropout)(dnn_input) dnn_logit = Dense(1, use_bias=False)(dnn_out) final_logit = add_func([dnn_logit, linear_logit]) output = PredictionLayer(task)(final_logit) model = Model(inputs=inputs_list, outputs=output) return model
def feature_embedding(fc_i, fc_j, embedding_dict, input_feature): fc_i_embedding = embedding_dict[fc_i.name][fc_j.name](input_feature) if isinstance(fc_i, SparseFeat): return NoMask()(fc_i_embedding) else: return SequencePoolingLayer(fc_i.combiner, supports_masking=True)(fc_i_embedding)