Python v1.argsort方法代码示例

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def _select_top_k(logits, top_k):
  """Replaces logits, expect the top k highest values, with small number (-1e6).

  If k is -1 don't replace anything.

  Args:
    logits: A `Tensor` of shape [batch_size, ..., vocab_size]
    top_k: vector of batch size.

  Returns:
    A `Tensor` with same shape  as logits.
  """
  vocab_size = logits.shape[-1]

  top_k = tf.where(
      tf.not_equal(top_k, -1), top_k,
      tf.ones_like(top_k) * vocab_size)

  return tf.where(
      tf.argsort(logits) < tf.reshape(top_k, [-1] + [1] *
                                      (len(logits.shape) - 1)), logits,
      tf.ones_like(logits) * -1e6) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def _classification_loss(self, pred_label, gt_label, num_matched_boxes):
    """Computes the classification loss.

    Computes the classification loss with hard negative mining.
    Args:
      pred_label: a flatten tensor that includes all predicted class. The shape
        is [batch_size, num_anchors, num_classes].
      gt_label: a tensor that represents the classification groundtruth targets.
        The shape is [batch_size, num_anchors, 1].
      num_matched_boxes: the number of anchors that are matched to a groundtruth
        targets. This is used as the loss normalizater.

    Returns:
      box_loss: a float32 representing total box regression loss.
    """
    cross_entropy = tf.losses.sparse_softmax_cross_entropy(
        gt_label, pred_label, reduction=tf.losses.Reduction.NONE)

    mask = tf.greater(tf.squeeze(gt_label), 0)
    float_mask = tf.cast(mask, tf.float32)

    # Hard example mining
    neg_masked_cross_entropy = cross_entropy * (1 - float_mask)
    relative_position = tf.argsort(
        tf.argsort(
            neg_masked_cross_entropy, direction='DESCENDING'))
    num_neg_boxes = tf.minimum(
        tf.to_int32(num_matched_boxes) * ssd_constants.NEGS_PER_POSITIVE,
        ssd_constants.NUM_SSD_BOXES)
    top_k_neg_mask = tf.cast(tf.less(
        relative_position,
        tf.tile(num_neg_boxes[:, tf.newaxis], (1, ssd_constants.NUM_SSD_BOXES))
    ), tf.float32)

    class_loss = tf.reduce_sum(
        tf.multiply(cross_entropy, float_mask + top_k_neg_mask), axis=1)

    return tf.reduce_mean(class_loss / num_matched_boxes) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def framework(msg='err'):
  """Return framework module or dummy version."""
  del msg
  if is_tf2:
    return DummyModule(
        arg_scope=None,
        get_name_scope=lambda: tf.get_default_graph().get_name_scope(),
        name_scope=tf.name_scope,
        deprecated=deprecated,
        nest=tf.nest,
        argsort=tf.argsort)

  from tensorflow.contrib import framework as contrib_framework  # pylint: disable=g-direct-tensorflow-import,g-import-not-at-top
  return contrib_framework 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def _top_k_sample(logits, ignore_ids=None, num_samples=1, k=10):
    """
    Does top-k sampling. if ignore_ids is on, then we will zero out those logits.
    :param logits: [batch_size, vocab_size] tensor
    :param ignore_ids: [vocab_size] one-hot representation of the indices we'd like to ignore and never predict,
                        like padding maybe
    :param p: topp threshold to use, either a float or a [batch_size] vector
    :return: [batch_size, num_samples] samples

    # TODO FIGURE OUT HOW TO DO THIS ON TPUS. IT'S HELLA SLOW RIGHT NOW, DUE TO ARGSORT I THINK
    """
    with tf.variable_scope('top_p_sample'):
        batch_size, vocab_size = get_shape_list(logits, expected_rank=2)

        probs = tf.nn.softmax(logits if ignore_ids is None else logits - tf.cast(ignore_ids[None], tf.float32) * 1e10,
                              axis=-1)
        # [batch_size, vocab_perm]
        indices = tf.argsort(probs, direction='DESCENDING')

        # find the top pth index to cut off. careful we don't want to cutoff everything!
        # result will be [batch_size, vocab_perm]
        k_expanded = k if isinstance(k, int) else k[:, None]
        exclude_mask = tf.range(vocab_size)[None] >= k_expanded

        # OPTION A - sample in the sorted space, then unsort.
        logits_to_use = tf.batch_gather(logits, indices) - tf.cast(exclude_mask, tf.float32) * 1e10
        sample_perm = tf.random.categorical(logits=logits_to_use, num_samples=num_samples)
        sample = tf.batch_gather(indices, sample_perm)

    return {
        'probs': probs,
        'sample': sample,
    } 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def nms_tf(dets, thresh):
  """Non-maximum suppression with tf graph mode."""
  x1 = dets[:, 0]
  y1 = dets[:, 1]
  x2 = dets[:, 2]
  y2 = dets[:, 3]
  scores = dets[:, 4]

  areas = (x2 - x1 + 1) * (y2 - y1 + 1)
  order = tf.argsort(scores, direction='DESCENDING')

  keep = tf.TensorArray(tf.int32, size=0, dynamic_size=True)
  index = 0
  while tf.size(order) > 0:
    i = order[0]
    keep = keep.write(index, i)
    xx1 = tf.maximum(x1[i], tf.gather(x1, order[1:]))
    yy1 = tf.maximum(y1[i], tf.gather(y1, order[1:]))
    xx2 = tf.minimum(x2[i], tf.gather(x2, order[1:]))
    yy2 = tf.minimum(y2[i], tf.gather(y2, order[1:]))

    w = tf.maximum(0.0, xx2 - xx1 + 1)
    h = tf.maximum(0.0, yy2 - yy1 + 1)
    intersection = w * h
    overlap = intersection / (
        areas[i] + tf.gather(areas, order[1:]) - intersection)

    inds = tf.where_v2(overlap <= thresh)
    order = tf.concat(tf.gather(order, inds + 1), axis=1)
    order = tf.squeeze(order, axis=-1)
    index += 1
  return keep.stack() 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def nms(dets, thresh):
  """Non-maximum suppression."""
  x1 = dets[:, 0]
  y1 = dets[:, 1]
  x2 = dets[:, 2]
  y2 = dets[:, 3]
  scores = dets[:, 4]

  areas = (x2 - x1 + 1) * (y2 - y1 + 1)
  order = scores.argsort()[::-1]

  keep = []
  while order.size > 0:
    i = order[0]
    keep.append(i)
    xx1 = np.maximum(x1[i], x1[order[1:]])
    yy1 = np.maximum(y1[i], y1[order[1:]])
    xx2 = np.minimum(x2[i], x2[order[1:]])
    yy2 = np.minimum(y2[i], y2[order[1:]])

    w = np.maximum(0.0, xx2 - xx1 + 1)
    h = np.maximum(0.0, yy2 - yy1 + 1)
    intersection = w * h
    overlap = intersection / (areas[i] + areas[order[1:]] - intersection)

    inds = np.where(overlap <= thresh)[0]
    order = order[inds + 1]
  return keep 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def _top_p_sample(logits, ignore_ids=None, num_samples=1, p=0.9):
    """
    Does top-p sampling. if ignore_ids is on, then we will zero out those logits.
    :param logits: [batch_size, vocab_size] tensor
    :param ignore_ids: [vocab_size] one-hot representation of the indices we'd like to ignore and never predict,
                        like padding maybe
    :param p: topp threshold to use, either a float or a [batch_size] vector
    :return: [batch_size, num_samples] samples

    # TODO FIGURE OUT HOW TO DO THIS ON TPUS. IT'S HELLA SLOW RIGHT NOW, DUE TO ARGSORT I THINK
    """
    with tf.variable_scope('top_p_sample'):
        batch_size, vocab_size = get_shape_list(logits, expected_rank=2)

        probs = tf.nn.softmax(logits if ignore_ids is None else logits - tf.cast(ignore_ids[None], tf.float32) * 1e10,
                              axis=-1)

        if isinstance(p, float) and p > 0.999999:
            # Don't do top-p sampling in this case
            print("Top-p sampling DISABLED", flush=True)
            return {
                'probs': probs,
                'sample': tf.random.categorical(
                    logits=logits if ignore_ids is None else logits - tf.cast(ignore_ids[None], tf.float32) * 1e10,
                    num_samples=num_samples, dtype=tf.int32),
            }

        # [batch_size, vocab_perm]
        indices = tf.argsort(probs, direction='DESCENDING')
        cumulative_probabilities = tf.math.cumsum(tf.batch_gather(probs, indices), axis=-1, exclusive=False)

        # find the top pth index to cut off. careful we don't want to cutoff everything!
        # result will be [batch_size, vocab_perm]
        p_expanded = p if isinstance(p, float) else p[:, None]
        exclude_mask = tf.logical_not(
            tf.logical_or(cumulative_probabilities < p_expanded, tf.range(vocab_size)[None] < 1))

        # OPTION A - sample in the sorted space, then unsort.
        logits_to_use = tf.batch_gather(logits, indices) - tf.cast(exclude_mask, tf.float32) * 1e10
        sample_perm = tf.random.categorical(logits=logits_to_use, num_samples=num_samples)
        sample = tf.batch_gather(indices, sample_perm)

        # OPTION B - unsort first - Indices need to go back to 0 -> N-1 -- then sample
        # unperm_indices = tf.argsort(indices, direction='ASCENDING')
        # include_mask_unperm = tf.batch_gather(include_mask, unperm_indices)
        # logits_to_use = logits - (1 - tf.cast(include_mask_unperm, tf.float32)) * 1e10
        # sample = tf.random.categorical(logits=logits_to_use, num_samples=num_samples, dtype=tf.int32)

    return {
        'probs': probs,
        'sample': sample,
    } 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import argsort [as 别名]
def sp_mul(sp_a_indices, sp_a_values, sp_b, default_value=0.):
  """Element-wise multiply two SparseTensors.

  One SparseTensor has a fixed number of non-zero values, represented in the
  form of a B x K matrix of indices and the other in a B x K matrix of values.

  Args:
    sp_a_indices: B x K Tensor. Indices into M values.
    sp_a_values: B x K Tensor.
    sp_b: B x M SparseTensor.
    default_value: Scalar default value to use for indices which do not
      intersect.

  Returns:
    mul_values: B x K Tensor corresponding to indices in sp_a_indices. For
      indices also present in sp_b the output is the product of the values in
      sp_a_values. For those absent in sp_b, the output is default_value.
  """
  batch_size = tf.shape(sp_a_indices)[0]
  num_neighbors = tf.shape(sp_a_indices)[1]
  a_values = tf.reshape(sp_a_values, (batch_size * num_neighbors,))
  brange = tf.tile(
      tf.expand_dims(tf.cast(tf.range(batch_size), sp_a_indices.dtype), 1),
      (1, num_neighbors))
  nnz_indices = tf.stack([brange, sp_a_indices], axis=2)
  nnz_indices = tf.reshape(nnz_indices, (batch_size * num_neighbors, 2))

  # Linearize
  scaling_vector = tf.cumprod(tf.cast(tf.shape(sp_b), sp_b.indices.dtype))
  a1s = tf.linalg.matvec(
      tf.cast(nnz_indices, sp_b.indices.dtype), scaling_vector)
  b1s = tf.linalg.matvec(sp_b.indices, scaling_vector)

  # Get intersections.
  a_nonint, _ = tf.setdiff1d(a1s, b1s)
  a_int, a_int_idx = tf.setdiff1d(a1s, a_nonint)
  b_nonint, _ = tf.setdiff1d(b1s, a1s)
  b_int, b_int_idx = tf.setdiff1d(b1s, b_nonint)

  # Get sorting.
  a_int_sort_ind = tf.argsort(a_int)
  b_int_sort_ind = tf.argsort(b_int)

  # Multiply.
  int_vals = (
      tf.gather(a_values, tf.gather(a_int_idx, a_int_sort_ind)) *
      tf.gather(sp_b.values, tf.gather(b_int_idx, b_int_sort_ind)))
  int_vals_dense = tf.sparse_to_dense(
      sparse_indices=tf.expand_dims(tf.gather(a_int_idx, a_int_sort_ind), 1),
      output_shape=tf.shape(a_values),
      default_value=default_value,
      sparse_values=int_vals,
      validate_indices=False)

  return tf.reshape(int_vals_dense, (batch_size, num_neighbors))