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Looks up embeddings for the given ids from a list of tensors.
tf.compat.v1.nn.embedding_lookup(
params, ids, partition_strategy='mod', name=None,
validate_indices=True, max_norm=None
)
This function is used to perform parallel lookups on the list of tensors in
params. It is a generalization of tf.gather, where params is
interpreted as a partitioning of a large embedding tensor. params may be
a PartitionedVariable as returned by using tf.compat.v1.get_variable()
with a partitioner.
If len(params) > 1, each element id of ids is partitioned between
the elements of params according to the partition_strategy.
In all strategies, if the id space does not evenly divide the number of
partitions, each of the first (max_id + 1) % len(params) partitions will
be assigned one more id.
If partition_strategy is "mod", we assign each id to partition
p = id % len(params). For instance,
13 ids are split across 5 partitions as:
[[0, 5, 10], [1, 6, 11], [2, 7, 12], [3, 8], [4, 9]]
If partition_strategy is "div", we assign ids to partitions in a
contiguous manner. In this case, 13 ids are split across 5 partitions as:
[[0, 1, 2], [3, 4, 5], [6, 7, 8], [9, 10], [11, 12]]
If the input ids are ragged tensors, partition variables are not supported and
the partition strategy and the max_norm are ignored.
The results of the lookup are concatenated into a dense
tensor. The returned tensor has shape shape(ids) + shape(params)[1:].
Args | |
|---|---|
params
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A single tensor representing the complete embedding tensor, or a
list of P tensors all of same shape except for the first dimension,
representing sharded embedding tensors. Alternatively, a
PartitionedVariable, created by partitioning along dimension 0. Each
element must be appropriately sized for the given partition_strategy.
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ids
|
A Tensor or a 'RaggedTensor' with type int32 or int64 containing
the ids to be looked up in params.
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partition_strategy
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A string specifying the partitioning strategy, relevant
if len(params) > 1. Currently "div" and "mod" are supported. Default
is "mod".
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name
|
A name for the operation (optional). |
validate_indices
|
DEPRECATED. If this operation is assigned to CPU, values
in indices are always validated to be within range. If assigned to GPU,
out-of-bound indices result in safe but unspecified behavior, which may
include raising an error.
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max_norm
|
If not None, each embedding is clipped if its l2-norm is larger
than this value.
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Returns | |
|---|---|
A Tensor or a 'RaggedTensor', depending on the input, with the same type
as the tensors in params.
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Raises | |
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ValueError
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If params is empty.
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