Python tensorflow.strided_slice函数代码示例

def read_cifar10(filename_queue):
    class CIFAR10Record(object):
        pass

    result = CIFAR10Record()

    label_bytes = 1
    result.height = 32
    result.width = 32
    result.depth = 3
    image_bytes = result.height * result.width * result.depth
    record_bytes = label_bytes + image_bytes

    # Read a record, getting filenames from the filename_queue.
    reader = tf.FixedLengthRecordReader(record_bytes=record_bytes)
    result.key, value = reader.read(filename_queue)

    # Convert from a string to a vector of uint8 that is record_bytes long.
    record_bytes = tf.decode_raw(value, tf.uint8)

    # The first bytes represent the label, which we convert from uint8->int32.
    result.label = tf.cast(tf.strided_slice(record_bytes, [0], [label_bytes]), tf.int32)

    # The remaining bytes after the label represent the image, which we reshape
    # from [depth * height * width] to [depth, height, width].
    depth_major = tf.reshape(
        tf.strided_slice(record_bytes, [label_bytes],
                         [label_bytes + image_bytes]),
        [result.depth, result.height, result.width])

    # Convert from [depth, height, width] to [height, width, depth].
    result.uint8image = tf.transpose(depth_major, [1, 2, 0])

    return result

def _read_input(filename_queue):
  """Reads a single record and converts it to a tensor.

  Each record consists the 3x32x32 image with one byte for the label.

  Args:
    filename_queue: A queue of strings with the filenames to read from.

  Returns:
      image: a [32, 32, 3] float32 Tensor with the image data.
      label: an int32 Tensor with the label in the range 0..9.
  """
  label_bytes = 1
  height = 32
  depth = 3
  image_bytes = height * height * depth
  record_bytes = label_bytes + image_bytes

  reader = tf.FixedLengthRecordReader(record_bytes=record_bytes)
  _, byte_data = reader.read(filename_queue)
  uint_data = tf.decode_raw(byte_data, tf.uint8)

  label = tf.cast(tf.strided_slice(uint_data, [0], [label_bytes]), tf.int32)
  label.set_shape([1])

  depth_major = tf.reshape(
      tf.strided_slice(uint_data, [label_bytes], [record_bytes]),
      [depth, height, height])
  image = tf.cast(tf.transpose(depth_major, [1, 2, 0]), tf.float32)

  return image, label

def ptb_producer(raw_data, batch_size, num_steps, name=None):
    
    with tf.name_scope(name, "PTBProducer", [raw_data, batch_size, num_steps]):
        raw_data = tf.convert_to_tensor(raw_data, 
                                        dtype=tf.int32, name="raw_data")
        data_len = tf.size(raw_data)
        batch_len = data_len // batch_size
        data = tf.reshape(raw_data[0: batch_len*batch_size],
                          [batch_size, batch_len])
        epoch_size = (batch_len-1) // num_steps
        assertion = tf.assert_positive(
                epoch_size,
                message="batch size too large")
        
        with tf.control_dependencies([assertion]):
            epoch_size = tf.identity(epoch_size, name="epoch_size")
        
        i = tf.train.range_input_producer(epoch_size, shuffle=False).dequeue()
        x = tf.strided_slice(data, [0, i*num_steps],
                             [batch_size, (i+1)*num_steps])
        
        x.set_shape([batch_size, num_steps])
        y = tf.strided_slice(data, [0, i*num_steps+1],
                             [batch_size, (i+1)*num_steps+1])
        y.set_shape([batch_size, num_steps])
        return x, y

def read_data(file_q):
    # Code from https://github.com/tensorflow/models/blob/master/tutorials/image/cifar10/cifar10_input.py
    class CIFAR10Record(object):
        pass

    result = CIFAR10Record()

    # Dimensions of the images in the CIFAR-10 dataset.
    # See http://www.cs.toronto.edu/~kriz/cifar.html for a description of the
    # input format.
    label_bytes = 1  # 2 for CIFAR-100
    result.height = 32
    result.width = 32
    result.depth = 3
    image_bytes = result.height * result.width * result.depth
    # Every record consists of a label followed by the image, with a
    # fixed number of bytes for each.
    record_bytes = label_bytes + image_bytes

    # Read a record, getting filenames from the filename_queue.  No
    # header or footer in the CIFAR-10 format, so we leave header_bytes
    # and footer_bytes at their default of 0.
    reader = tf.FixedLengthRecordReader(record_bytes=record_bytes)
    result.key, value = reader.read(file_q)

    # Convert from a string to a vector of uint8 that is record_bytes long.
    record_bytes = tf.decode_raw(value, tf.uint8)

    # The first bytes represent the label, which we convert from uint8->int32.
    result.label = tf.cast(
        tf.strided_slice(record_bytes, [0], [label_bytes]), tf.int32)

    # The remaining bytes after the label represent the image, which we reshape
    # from [depth * height * width] to [depth, height, width].
    depth_major = tf.reshape(
        tf.strided_slice(record_bytes, [label_bytes],
                         [label_bytes + image_bytes]),
        [result.depth, result.height, result.width])
    # Convert from [depth, height, width] to [height, width, depth].
    result.uint8image = tf.transpose(depth_major, [1, 2, 0])

    reshaped_image = tf.cast(result.uint8image, tf.float32)

    height = 24
    width = 24

    # Image processing for evaluation.
    # Crop the central [height, width] of the image.
    resized_image = tf.image.resize_image_with_crop_or_pad(reshaped_image,
                                                           height, width)

    # Subtract off the mean and divide by the variance of the pixels.
    float_image = tf.image.per_image_standardization(resized_image)

    # Set the shapes of tensors.
    float_image.set_shape([height, width, 3])
    result.label.set_shape([1])

    return float_image, result.label

def read_cifar10(filename_queue):
  """Reads and parses examples from CIFAR10 data files.
  Recommendation: if you want N-way read parallelism, call this function
  N times.  This will give you N independent Readers reading different
  files & positions within those files, which will give better mixing of
  examples.
  Args:
    filename_queue: A queue of strings with the filenames to read from.
  Returns:
    An object representing a single example, with the following fields:
      height: number of rows in the result (32)
      width: number of columns in the result (32)
      depth: number of color channels in the result (3)
      key: a scalar string Tensor describing the filename & record number
        for this example.
      label: an int32 Tensor with the label in the range 0..9.
      uint8image: a [height, width, depth] uint8 Tensor with the image data
  """

  class CIFAR10Record(object):
    pass
  result = CIFAR10Record()

  # Dimensions of the images in the CIFAR-10 dataset.
  # See http://www.cs.toronto.edu/~kriz/cifar.html for a description of the
  # input format.
  label_bytes = 1  # 2 for CIFAR-100
  result.height = 32
  result.width = 32
  result.depth = 3
  image_bytes = result.height * result.width * result.depth
  # Every record consists of a label followed by the image, with a
  # fixed number of bytes for each.
  record_bytes = label_bytes + image_bytes

  # Read a record, getting filenames from the filename_queue.  No
  # header or footer in the CIFAR-10 format, so we leave header_bytes
  # and footer_bytes at their default of 0.
  reader = tf.FixedLengthRecordReader(record_bytes=record_bytes)
  result.key, value = reader.read(filename_queue)

  # Convert from a string to a vector of uint8 that is record_bytes long.
  record_bytes = tf.decode_raw(value, tf.uint8)

  # The first bytes represent the label, which we convert from uint8->int32.
  result.label = tf.cast(
      tf.strided_slice(record_bytes, [0], [label_bytes]), tf.int32)

  # The remaining bytes after the label represent the image, which we reshape
  # from [depth * height * width] to [depth, height, width].
  depth_major = tf.reshape(
      tf.strided_slice(record_bytes, [label_bytes],
                       [label_bytes + image_bytes]),
      [result.depth, result.height, result.width])
  # Convert from [depth, height, width] to [height, width, depth].
  result.uint8image = tf.transpose(depth_major, [1, 2, 0])

  return result

  def __init__(self, **kwargs):
    """
    """
    super(AlternatingRealToComplexLayer, self).__init__(**kwargs)

    input_placeholder = self.input_data.get_placeholder_as_batch_major()

    real_value = tf.strided_slice(input_placeholder, [0, 0, 0], tf.shape(input_placeholder), [1, 1, 2])
    imag_value = tf.strided_slice(input_placeholder, [0, 0, 1], tf.shape(input_placeholder), [1, 1, 2])
    self.output.placeholder = tf.complex(real_value, imag_value)
    self.output.size_placeholder = {0: self.input_data.size_placeholder[self.input_data.time_dim_axis_excluding_batch]}

 def _build_clp_multiplication(self, clp_kernel):
   from TFUtil import safe_log
   input_placeholder = self.input_data.get_placeholder_as_batch_major()
   tf.assert_equal(tf.shape(clp_kernel)[1], tf.shape(input_placeholder)[2] // 2)
   tf.assert_equal(tf.shape(clp_kernel)[2], self._nr_of_filters)
   input_real = tf.strided_slice(input_placeholder, [0, 0, 0], tf.shape(input_placeholder), [1, 1, 2])
   input_imag = tf.strided_slice(input_placeholder, [0, 0, 1], tf.shape(input_placeholder), [1, 1, 2])
   kernel_real = self._clp_kernel[0, :, :]
   kernel_imag = self._clp_kernel[1, :, :]
   output_real = tf.einsum('btf,fp->btp', input_real, kernel_real) - tf.einsum('btf,fp->btp', input_imag, kernel_imag)
   output_imag = tf.einsum('btf,fp->btp', input_imag, kernel_real) + tf.einsum('btf,fp->btp', input_real, kernel_imag)
   output_uncompressed = tf.sqrt(tf.pow(output_real, 2) + tf.pow(output_imag, 2))
   output_compressed = safe_log(output_uncompressed)
   return output_compressed

def _test_stridedslice(ip_shape, begin, end, stride, dtype,
                             begin_mask=0, end_mask=0, new_axis_mask=0,
                             shrink_axis_mask=0, ellipsis_mask=0):
    """ One iteration of a Stridedslice """

    tf.reset_default_graph()
    in_data = tf.placeholder(dtype, ip_shape, name="in_data")
    tf.strided_slice(in_data, begin, end, stride, begin_mask=begin_mask,
                         end_mask=end_mask, new_axis_mask=new_axis_mask,
                         shrink_axis_mask=shrink_axis_mask,
                         ellipsis_mask=ellipsis_mask, name="strided_slice")
    np_data = np.random.uniform(size=ip_shape).astype(dtype)

    compare_tf_with_tvm(np_data, 'in_data:0', 'strided_slice:0')

def read_cifar10(filename_queue):
    """Reads and parses examples from CIFAR10 data files.

    Recommendation: if you want N-way read parallelism, call this function
    N times.  This will give you N independent Readers reading different
    files & positions within those files, which will give better mixing of
    examples.

    Args:
    filename_queue: A queue of strings with the filenames to read from.

    Returns:
        An object representing a single example, with the following fields:
        height: number of rows in the result (32)
        width: number of columns in the result (32)
        depth: number of color channels in the result (3)
        key: a scalar string Tensor describing the filename & record number
            for this example.
        label: an int32 Tensor with the label in the range 0..9.
        uint8image: a [height, width, depth] uint8 Tensor with the image data
    """

    class CIFAR10Record(object):
        pass
    result = CIFAR10Record()

    label_bytes = 1
    result.height, result.width, result.depth = 32, 32, 3
    image_bytes = result.height * result.width * result.depth
    record_bytes = label_bytes + image_bytes

    reader = tf.FixedLengthRecordReader(record_bytes=record_bytes)
    result.key, value = reader.read(filename_queue)

    # Convert from a string to a vector of uint8 that is record_bytes long.
    record_bytes = tf.decode_raw(value, tf.uint8)

    # The first bytes represent the label, which we convert from uint8->int32.
    result.label = tf.cast(tf.strided_slice(record_bytes, [0], [label_bytes]), tf.int32)

    # The remaining bytes after the label represent the image, which we reshape
    # from [depth * height * width] to [depth, height, width].
    depth_major = tf.reshape(tf.strided_slice(record_bytes, [label_bytes],
                                              [label_bytes + image_bytes]),
                             [result.depth, result.height, result.width])
    # Convert from [depth, height, width] to [height, width, depth].
    result.uint8image = tf.transpose(depth_major, [1, 2, 0])

    return result

def process_encoding_input(target_data, vocab_to_int, batch_size):
    '''Remove the last word id from each batch and concat the <GO> to the begining of each batch'''
    
    ending = tf.strided_slice(target_data, [0, 0], [batch_size, -1], [1, 1])
    dec_input = tf.concat([tf.fill([batch_size, 1], vocab_to_int['<GO>']), ending], 1)

    return dec_input

def AddCrossEntropy(batch_size, n):
  """Adds a cross entropy cost function."""
  cross_entropies = []
  def _Pass():
    return tf.constant(0, dtype=tf.float32, shape=[1])

  for beam_id in range(batch_size):
    beam_gold_slot = tf.reshape(
        tf.strided_slice(n['gold_slot'], [beam_id], [beam_id + 1]), [1])
    def _ComputeCrossEntropy():
      """Adds ops to compute cross entropy of the gold path in a beam."""
      # Requires a cast so that UnsortedSegmentSum, in the gradient,
      # is happy with the type of its input 'segment_ids', which
      # must be int32.
      idx = tf.cast(
          tf.reshape(
              tf.where(tf.equal(n['beam_ids'], beam_id)), [-1]), tf.int32)
      beam_scores = tf.reshape(tf.gather(n['all_path_scores'], idx), [1, -1])
      num = tf.shape(idx)
      return tf.nn.softmax_cross_entropy_with_logits(
          labels=tf.expand_dims(
              tf.sparse_to_dense(beam_gold_slot, num, [1.], 0.), 0),
          logits=beam_scores)
    # The conditional here is needed to deal with the last few batches of the
    # corpus which can contain -1 in beam_gold_slot for empty batch slots.
    cross_entropies.append(cf.cond(
        beam_gold_slot[0] >= 0, _ComputeCrossEntropy, _Pass))
  return {'cross_entropy': tf.div(tf.add_n(cross_entropies), batch_size)}

        def objective(x):
            """Rosenbrock function. (Carl Edward Rasmussen, 2001-07-21).

      f(x) = sum_{i=1:D-1} 100*(x(i+1) - x(i)^2)^2 + (1-x(i))^2

      Args:
        x: a Variable
      Returns:
        f: a tensor (objective value)
      """

            d = tf.size(x)
            s = tf.add(
                100 * tf.square(tf.sub(tf.strided_slice(x, [1], [d]), tf.square(tf.strided_slice(x, [0], [d - 1])))),
                tf.square(tf.sub(1.0, tf.strided_slice(x, [0], [d - 1]))),
            )
            return tf.reduce_sum(s)

 def _my_metric_op(predictions, labels):
   # For the case of binary classification, the 2nd column of "predictions"
   # denotes the model predictions.
   labels = tf.to_float(labels)
   predictions = tf.strided_slice(
       predictions, [0, 1], [-1, 2], end_mask=1)
   labels = math_ops.cast(labels, predictions.dtype)
   return tf.reduce_sum(tf.multiply(predictions, labels))

def process_decoder_input(data, vocab_to_int, batch_size):
    '''
    补充<GO>，并移除最后一个字符
    '''
    # cut掉最后一个字符
    ending = tf.strided_slice(data, [0, 0], [batch_size, -1], [1, 1])
    decoder_input = tf.concat([tf.fill([batch_size, 1], vocab_to_int['<GO>']), ending], 1)

    return decoder_input

    def gather(self, src, force_copy=False):
        """
        Fetches the data corresponding to ``src`` from the base array.

        Parameters
        ----------
        src : `.TensorSignal`
            Signal indicating the data to be read from base array
        force_copy : bool
            If True, always perform a gather, not a slice (this forces a
            copy). Note that setting ``force_copy=False`` does not guarantee
            that a copy won't be performed.

        Returns
        -------
        gathered : ``tf.Tensor``
            Tensor object corresponding to a dense subset of data from the
            base array
        """

        logger.debug("gather")
        logger.debug("src %s", src)
        logger.debug("indices %s", src.indices)
        logger.debug("src base %s", self.bases[src.key])

        var = self.bases[src.key]

        # we prefer to get the data via `strided_slice` or `identity` if
        # possible, as it is more efficient
        if force_copy or src.tf_slice is None:
            result = tf.gather(var, src.tf_indices)
            self.read_types["gather"] += 1
        elif (src.indices[0] == 0 and
              src.indices[-1] == var.get_shape()[0].value - 1 and
              len(src.indices) == var.get_shape()[0]):
            result = var
            self.read_types["identity"] += 1
        else:
            result = tf.strided_slice(var, *src.tf_slice)
            self.read_types["strided_slice"] += 1

        # reshape the data according to the shape set in `src`, if there is
        # one, otherwise keep the shape of the base array
        if result.get_shape() != src.full_shape:
            result = tf.reshape(result, src.tf_shape)

        # for some reason the shape inference doesn't work in some cases
        result.set_shape(src.full_shape)

        # whenever we read from an array we use this to mark it as "read"
        # (so that any future writes to the array will be scheduled after
        # the read)
        self.mark_gather(src)

        return result