Represents sparse feature where ids are set by hashing.
tf.feature_column.categorical_column_with_hash_bucket(
key, hash_bucket_size, dtype=tf.dtypes.string
)
Use this when your sparse features are in string or integer format, and you
want to distribute your inputs into a finite number of buckets by hashing.
output_id = Hash(input_feature_string) % bucket_size for string type input.
For int type input, the value is converted to its string representation first
and then hashed by the same formula.
For input dictionary features
, features[key]
is either Tensor
or
SparseTensor
. If Tensor
, missing values can be represented by -1
for int
and ''
for string, which will be dropped by this feature column.
Example:
import tensorflow as tf
keywords = tf.feature_column.categorical_column_with_hash_bucket("keywords",
10000)
columns = [keywords]
features = {'keywords': tf.constant([['Tensorflow', 'Keras', 'RNN', 'LSTM',
'CNN'], ['LSTM', 'CNN', 'Tensorflow', 'Keras', 'RNN'], ['CNN', 'Tensorflow',
'LSTM', 'Keras', 'RNN']])}
linear_prediction, _, _ = tf.compat.v1.feature_column.linear_model(features,
columns)
# or
import tensorflow as tf
keywords = tf.feature_column.categorical_column_with_hash_bucket("keywords",
10000)
keywords_embedded = tf.feature_column.embedding_column(keywords, 16)
columns = [keywords_embedded]
features = {'keywords': tf.constant([['Tensorflow', 'Keras', 'RNN', 'LSTM',
'CNN'], ['LSTM', 'CNN', 'Tensorflow', 'Keras', 'RNN'], ['CNN', 'Tensorflow',
'LSTM', 'Keras', 'RNN']])}
input_layer = tf.keras.layers.DenseFeatures(columns)
dense_tensor = input_layer(features)
Args |
key
|
A unique string identifying the input feature. It is used as the
column name and the dictionary key for feature parsing configs, feature
Tensor objects, and feature columns.
|
hash_bucket_size
|
An int > 1. The number of buckets.
|
dtype
|
The type of features. Only string and integer types are supported.
|
Returns |
A HashedCategoricalColumn .
|
Raises |
ValueError
|
hash_bucket_size is not greater than 1.
|
ValueError
|
dtype is neither string nor integer.
|