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diff --git a/tensorflow/docs_src/tutorials/wide_and_deep.md b/tensorflow/docs_src/tutorials/wide_and_deep.md deleted file mode 100644 index 44677a810b..0000000000 --- a/tensorflow/docs_src/tutorials/wide_and_deep.md +++ /dev/null @@ -1,243 +0,0 @@ -# TensorFlow Wide & Deep Learning Tutorial - -In the previous @{$wide$TensorFlow Linear Model Tutorial}, we trained a logistic -regression model to predict the probability that the individual has an annual -income of over 50,000 dollars using the -[Census Income Dataset](https://archive.ics.uci.edu/ml/datasets/Census+Income). -TensorFlow is great for training deep neural networks too, and you might be -thinking which one you should choose—well, why not both? Would it be possible to -combine the strengths of both in one model? - -In this tutorial, we'll introduce how to use the tf.estimator API to jointly -train a wide linear model and a deep feed-forward neural network. This approach -combines the strengths of memorization and generalization. It's useful for -generic large-scale regression and classification problems with sparse input -features (e.g., categorical features with a large number of possible feature -values). If you're interested in learning more about how Wide & Deep Learning -works, please check out our [research paper](https://arxiv.org/abs/1606.07792). - - - -The figure above shows a comparison of a wide model (logistic regression with -sparse features and transformations), a deep model (feed-forward neural network -with an embedding layer and several hidden layers), and a Wide & Deep model -(joint training of both). At a high level, there are only 3 steps to configure a -wide, deep, or Wide & Deep model using the tf.estimator API: - -1. Select features for the wide part: Choose the sparse base columns and - crossed columns you want to use. -1. Select features for the deep part: Choose the continuous columns, the - embedding dimension for each categorical column, and the hidden layer sizes. -1. Put them all together in a Wide & Deep model - (`DNNLinearCombinedClassifier`). - -And that's it! Let's go through a simple example. - -## Setup - -To try the code for this tutorial: - -1. @{$install$Install TensorFlow} if you haven't already. - -2. Download [the tutorial code](https://github.com/tensorflow/models/tree/master/official/wide_deep/). - -3. Execute the data download script we provide to you: - - $ python data_download.py - -4. Execute the tutorial code with the following command to train the wide and -deep model described in this tutorial: - - $ python wide_deep.py - -Read on to find out how this code builds its model. - - -## Define Base Feature Columns - -First, let's define the base categorical and continuous feature columns that -we'll use. These base columns will be the building blocks used by both the wide -part and the deep part of the model. - -```python -import tensorflow as tf - -# Continuous columns -age = tf.feature_column.numeric_column('age') -education_num = tf.feature_column.numeric_column('education_num') -capital_gain = tf.feature_column.numeric_column('capital_gain') -capital_loss = tf.feature_column.numeric_column('capital_loss') -hours_per_week = tf.feature_column.numeric_column('hours_per_week') - -education = tf.feature_column.categorical_column_with_vocabulary_list( - 'education', [ - 'Bachelors', 'HS-grad', '11th', 'Masters', '9th', 'Some-college', - 'Assoc-acdm', 'Assoc-voc', '7th-8th', 'Doctorate', 'Prof-school', - '5th-6th', '10th', '1st-4th', 'Preschool', '12th']) - -marital_status = tf.feature_column.categorical_column_with_vocabulary_list( - 'marital_status', [ - 'Married-civ-spouse', 'Divorced', 'Married-spouse-absent', - 'Never-married', 'Separated', 'Married-AF-spouse', 'Widowed']) - -relationship = tf.feature_column.categorical_column_with_vocabulary_list( - 'relationship', [ - 'Husband', 'Not-in-family', 'Wife', 'Own-child', 'Unmarried', - 'Other-relative']) - -workclass = tf.feature_column.categorical_column_with_vocabulary_list( - 'workclass', [ - 'Self-emp-not-inc', 'Private', 'State-gov', 'Federal-gov', - 'Local-gov', '?', 'Self-emp-inc', 'Without-pay', 'Never-worked']) - -# To show an example of hashing: -occupation = tf.feature_column.categorical_column_with_hash_bucket( - 'occupation', hash_bucket_size=1000) - -# Transformations. -age_buckets = tf.feature_column.bucketized_column( - age, boundaries=[18, 25, 30, 35, 40, 45, 50, 55, 60, 65]) -``` - -## The Wide Model: Linear Model with Crossed Feature Columns - -The wide model is a linear model with a wide set of sparse and crossed feature -columns: - -```python -base_columns = [ - education, marital_status, relationship, workclass, occupation, - age_buckets, -] - -crossed_columns = [ - tf.feature_column.crossed_column( - ['education', 'occupation'], hash_bucket_size=1000), - tf.feature_column.crossed_column( - [age_buckets, 'education', 'occupation'], hash_bucket_size=1000), -] -``` - -You can also see the @{$wide$TensorFlow Linear Model Tutorial} for more details. - -Wide models with crossed feature columns can memorize sparse interactions -between features effectively. That being said, one limitation of crossed feature -columns is that they do not generalize to feature combinations that have not -appeared in the training data. Let's add a deep model with embeddings to fix -that. - -## The Deep Model: Neural Network with Embeddings - -The deep model is a feed-forward neural network, as shown in the previous -figure. Each of the sparse, high-dimensional categorical features are first -converted into a low-dimensional and dense real-valued vector, often referred to -as an embedding vector. These low-dimensional dense embedding vectors are -concatenated with the continuous features, and then fed into the hidden layers -of a neural network in the forward pass. The embedding values are initialized -randomly, and are trained along with all other model parameters to minimize the -training loss. If you're interested in learning more about embeddings, check out -the TensorFlow tutorial on @{$word2vec$Vector Representations of Words} or -[Word embedding](https://en.wikipedia.org/wiki/Word_embedding) on Wikipedia. - -Another way to represent categorical columns to feed into a neural network is -via a one-hot or multi-hot representation. This is often appropriate for -categorical columns with only a few possible values. As an example of a one-hot -representation, for the relationship column, `"Husband"` can be represented as -[1, 0, 0, 0, 0, 0], and `"Not-in-family"` as [0, 1, 0, 0, 0, 0], etc. This is a -fixed representation, whereas embeddings are more flexible and calculated at -training time. - -We'll configure the embeddings for the categorical columns using -`embedding_column`, and concatenate them with the continuous columns. -We also use `indicator_column` to create multi-hot representations of some -categorical columns. - -```python -deep_columns = [ - age, - education_num, - capital_gain, - capital_loss, - hours_per_week, - tf.feature_column.indicator_column(workclass), - tf.feature_column.indicator_column(education), - tf.feature_column.indicator_column(marital_status), - tf.feature_column.indicator_column(relationship), - # To show an example of embedding - tf.feature_column.embedding_column(occupation, dimension=8), -] -``` - -The higher the `dimension` of the embedding is, the more degrees of freedom the -model will have to learn the representations of the features. For simplicity, we -set the dimension to 8 for all feature columns here. Empirically, a more -informed decision for the number of dimensions is to start with a value on the -order of \\(\log_2(n)\\) or \\(k\sqrt[4]n\\), where \\(n\\) is the number of -unique features in a feature column and \\(k\\) is a small constant (usually -smaller than 10). - -Through dense embeddings, deep models can generalize better and make predictions -on feature pairs that were previously unseen in the training data. However, it -is difficult to learn effective low-dimensional representations for feature -columns when the underlying interaction matrix between two feature columns is -sparse and high-rank. In such cases, the interaction between most feature pairs -should be zero except a few, but dense embeddings will lead to nonzero -predictions for all feature pairs, and thus can over-generalize. On the other -hand, linear models with crossed features can memorize these “exception rules” -effectively with fewer model parameters. - -Now, let's see how to jointly train wide and deep models and allow them to -complement each other’s strengths and weaknesses. - -## Combining Wide and Deep Models into One - -The wide models and deep models are combined by summing up their final output -log odds as the prediction, then feeding the prediction to a logistic loss -function. All the graph definition and variable allocations have already been -handled for you under the hood, so you simply need to create a -`DNNLinearCombinedClassifier`: - -```python -model = tf.estimator.DNNLinearCombinedClassifier( - model_dir='/tmp/census_model', - linear_feature_columns=base_columns + crossed_columns, - dnn_feature_columns=deep_columns, - dnn_hidden_units=[100, 50]) -``` - -## Training and Evaluating The Model - -Before we train the model, let's read in the Census dataset as we did in the -@{$wide$TensorFlow Linear Model tutorial}. See `data_download.py` as well as -`input_fn` within -[`wide_deep.py`](https://github.com/tensorflow/models/tree/master/official/wide_deep/wide_deep.py). - -After reading in the data, you can train and evaluate the model: - -```python -# Train and evaluate the model every `FLAGS.epochs_per_eval` epochs. -for n in range(FLAGS.train_epochs // FLAGS.epochs_per_eval): - model.train(input_fn=lambda: input_fn( - FLAGS.train_data, FLAGS.epochs_per_eval, True, FLAGS.batch_size)) - - results = model.evaluate(input_fn=lambda: input_fn( - FLAGS.test_data, 1, False, FLAGS.batch_size)) - - # Display evaluation metrics - print('Results at epoch', (n + 1) * FLAGS.epochs_per_eval) - print('-' * 30) - - for key in sorted(results): - print('%s: %s' % (key, results[key])) -``` - -The final output accuracy should be somewhere around 85.5%. If you'd like to -see a working end-to-end example, you can download our -[example code](https://github.com/tensorflow/models/tree/master/official/wide_deep/wide_deep.py). - -Note that this tutorial is just a quick example on a small dataset to get you -familiar with the API. Wide & Deep Learning will be even more powerful if you -try it on a large dataset with many sparse feature columns that have a large -number of possible feature values. Again, feel free to take a look at our -[research paper](https://arxiv.org/abs/1606.07792) for more ideas about how to -apply Wide & Deep Learning in real-world large-scale machine learning problems. |