Tensorflow 开发者大会
Post date: Aug 21, 2017 2:19:45 PM
视频连接:https://www.youtube.com/playlist?list=PLwv-rHS37fS9sj62f4HAbqSrC1EiPsNZx
RNN for sequence
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# batch techniques for memory and computation saving.
# tf.train.batch() static batch, pad all sequences to the maximum length
# tf.train.batch(, dynamic_pad=True), pad batch sequences to the maximum batch length
# tf.contrib.training.bucket_by_sequence_length(,dynamic_pad=True), bucketed padding
# tf.contrib.training.batch_sequnces_with_states(), truncated BPTT via State Saver,
# cut sequence into pieces and save state from former pieces
#
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# dynamic calculation
# Tools:
# while_loop
# dynamic loops + gradients
# tf.TensorArray
# dynamic Tensor slice + gradients
# tf.nn.dynamic_rnn tf.contrib.seq2seq.dynamic_decode
########################
# seq2seq model
# 8 layers LSTM with residual connections
# each layer is on a seperated GPU
cell = MultiRNNCell( [ DeviceWrapper( ResidualWrapper( LSTMCell( num_units=512 ) ), device='gpu:%d' % i) for i in range(8) ] )
encoder_outputs, encoder_final_state = tf.nn.dynamic( cell, inputs, sequence_length, parallel_iterations=32, swap_memory=True)
# how to communicate between GPU
ML toolkits
Knowing algorithms is basic, and know how to computee in large-scale and distributed setting with big data is better.
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# kmeans clustering method
# Lloyd's algorithm, Kmeans++ init
# Full/mini batch training
# cosine/squared distance
# think about mini batch training.
# GMM
# Matrix factorization, Weighted alternating least squares, distributed computing for large data
# SVM, linear SVM, and nonlinear, with L1, L2 regularization
Distributed Tensorflow
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# model replica
# divide data into GPUs and gather results.
# three different types of data. parameters, and inputs, and intermediate values.
# pay attention to data transfermation between devices, and influence of asynchroneous and/or synchoneous mode on perfermance.
#
# fault tolerance by saving the parameters
Integrating Tensorflow with infrastructure
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# data preprocessing: spark, hadoop, capache beam
# Input data: from fastest to slowest
# tf.Example and tf.SquenceExample protocol buffers in TFRecords files
# Native TensorFlow ops to read CSV, JSON
# feed data directly from Python: easiest to use, useful for setting in Reinforcement Learning