Suppose I have a sparse matrix
A = tf.sparse.SparseTensor(indices=[[0,0],[1,1],[1,2]], values=[1,1,1],
dense_shape=[2,3])
and a dense vector
B = tf.constant([4,3,5])
The shape of matrix A and vector B are (2,3)
, (1,3)
respectively. I would like to element-wise multiply B with each row of A. The expected result is another sparse matrix, say
C = tf.sparse.SparseTensor(indices=[[0,0],[1,1],[1,2]], values=[4,3,5],
dense_shape=[2,3])
I know it would be relatively easy if A
is a dense matrix, but the dense size of A
is extremely large and most of the elements in A
are zero.
CodePudding user response:
Just multiplying with an asterisk *
works.
tf.reduce_all(tf.sparse.to_dense(A * B) == tf.sparse.to_dense(C))
<tf.Tensor: shape=(), dtype=bool, numpy=True>
Btw, B
has shape (3,)
, not (1, 3)
This is the result of this operation:
<tf.Tensor: shape=(2, 3), dtype=int32, numpy=
array([[4, 0, 0],
[0, 3, 5]])>
You could also have done this manually, but keep an eye on the broadcasting rules:
tf.sparse.SparseTensor(indices=A.indices, values=A.values * B,
dense_shape=A.dense_shape)