How to read sparse matrix from tfrecords?

[kohleth]

Hi,

I am trying to read a sparse matrix from tfrecords, but it doesn't seem to be picking up the shape and value.
What's the proper way of doing this?

library(keras)
library(tfdatasets)
library(tfrecords)
library(Matrix)

(mat=rsparsematrix(10,10,0.1))
write_tfrecords(list(x=mat),'sparse_matrix.tfrecords')

dataset=tfrecord_dataset('sparse_matrix.tfrecords')%>%
  dataset_batch(3,F)%>%
  dataset_map(function(example_proto){
    features=list(x=tf$VarLenFeature(tf$float32))
    tf$parse_example(example_proto,features)
  })

it=make_iterator_one_shot(dataset)
sess=tf$Session()
next_batch <- iterator_get_next(it)
sess$run(next_batch$x)  ## empty array
sess$run(tf$sparse_to_dense(sparse_indices=next_batch$x$indices,
                            output_shape=next_batch$x$dense_shape,
                            sparse_values=next_batch$x$values))  ## empty array