tf.nn.embedding_lookup_sparse(
params,
sp_ids,
sp_weights,
partition_strategy='mod',
name=None,
combiner=None,
max_norm=None
)
Defined in tensorflow/python/ops/embedding_ops.py
.
Computes embeddings for the given ids and weights.
This op assumes that there is at least one id for each row in the dense tensor represented by sp_ids (i.e. there are no rows with empty features), and that all the indices of sp_ids are in canonical row-major order.
It also assumes that all id values lie in the range [0, p0), where p0 is the sum of the size of params along dimension 0.
Args:
params
: 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, aPartitionedVariable
, created by partitioning along dimension 0. Each element must be appropriately sized for the givenpartition_strategy
.sp_ids
: N x MSparseTensor
of int64 ids where N is typically batch size and M is arbitrary.sp_weights
: either aSparseTensor
of float / double weights, orNone
to indicate all weights should be taken to be 1. If specified,sp_weights
must have exactly the same shape and indices assp_ids
.partition_strategy
: A string specifying the partitioning strategy, relevant iflen(params) > 1
. Currently"div"
and"mod"
are supported. Default is"mod"
. Seetf.nn.embedding_lookup
for more details.name
: Optional name for the op.combiner
: A string specifying the reduction op. Currently "mean", "sqrtn" and "sum" are supported. "sum" computes the weighted sum of the embedding results for each row. "mean" is the weighted sum divided by the total weight. "sqrtn" is the weighted sum divided by the square root of the sum of the squares of the weights.max_norm
: If notNone
, each embedding is clipped if its l2-norm is larger than this value, before combining.
Returns:
A dense tensor representing the combined embeddings for the
sparse ids. For each row in the dense tensor represented by sp_ids
, the op
looks up the embeddings for all ids in that row, multiplies them by the
corresponding weight, and combines these embeddings as specified.
In other words, if
shape(combined params) = [p0, p1, ..., pm]
and
shape(sp_ids) = shape(sp_weights) = [d0, d1, ..., dn]
then
shape(output) = [d0, d1, ..., dn-1, p1, ..., pm]
.
For instance, if params is a 10x20 matrix, and sp_ids / sp_weights are
[0, 0]: id 1, weight 2.0 [0, 1]: id 3, weight 0.5 [1, 0]: id 0, weight 1.0 [2, 3]: id 1, weight 3.0
with combiner
="mean", then the output will be a 3x20 matrix where
output[0, :] = (params[1, :] * 2.0 + params[3, :] * 0.5) / (2.0 + 0.5) output[1, :] = (params[0, :] * 1.0) / 1.0 output[2, :] = (params[1, :] * 3.0) / 3.0
Raises:
TypeError
: Ifsp_ids
is not aSparseTensor
, or ifsp_weights
is neitherNone
norSparseTensor
.ValueError
: Ifcombiner
is not one of {"mean", "sqrtn", "sum"}.