tf.contrib.training.stratified_sample

tf.contrib.training.stratified_sample(
    tensors,
    labels,
    target_probs,
    batch_size,
    init_probs=None,
    enqueue_many=False,
    queue_capacity=16,
    threads_per_queue=1,
    name=None
)

Defined in tensorflow/contrib/training/python/training/sampling_ops.py.

See the guide: Training (contrib) > Online data resampling

Stochastically creates batches based on per-class probabilities.

This method discards examples. Internally, it creates one queue to amortize the cost of disk reads, and one queue to hold the properly-proportioned batch.

Args:

  • tensors: List of tensors for data. All tensors are either one item or a batch, according to enqueue_many.
  • labels: Tensor for label of data. Label is a single integer or a batch, depending on enqueue_many. It is not a one-hot vector.
  • target_probs: Target class proportions in batch. An object whose type has a registered Tensor conversion function.
  • batch_size: Size of batch to be returned.
  • init_probs: Class proportions in the data. An object whose type has a registered Tensor conversion function, or None for estimating the initial distribution.
  • enqueue_many: Bool. If true, interpret input tensors as having a batch dimension.
  • queue_capacity: Capacity of the large queue that holds input examples.
  • threads_per_queue: Number of threads for the large queue that holds input examples and for the final queue with the proper class proportions.
  • name: Optional prefix for ops created by this function.

Raises:

  • ValueError: If tensors isn't iterable.
  • ValueError: enqueue_many is True and labels doesn't have a batch dimension, or if enqueue_many is False and labels isn't a scalar.
  • ValueError: enqueue_many is True, and batch dimension on data and labels don't match.
  • ValueError: if probs don't sum to one.
  • ValueError: if a zero initial probability class has a nonzero target probability.
  • TFAssertion: if labels aren't integers in [0, num classes).

Returns:

(data_batch, label_batch), where data_batch is a list of tensors of the same length as tensors

Example: # Get tensor for a single data and label example. data, label = data_provider.Get(['data', 'label'])

# Get stratified batch according to per-class probabilities. target_probs = [...distribution you want...] [data_batch], labels = tf.contrib.training.stratified_sample( [data], label, target_probs)

# Run batch through network. ...