def concatenate()

in timesformer/utils/ava_evaluation/np_box_list_ops.py [0:0]

• 33 lines of code
• 12 McCabe index (conditional complexity)

def concatenate(boxlists, fields=None):
    """Concatenate list of BoxLists.

  This op concatenates a list of input BoxLists into a larger BoxList.  It also
  handles concatenation of BoxList fields as long as the field tensor shapes
  are equal except for the first dimension.

  Args:
    boxlists: list of BoxList objects
    fields: optional list of fields to also concatenate.  By default, all
      fields from the first BoxList in the list are included in the
      concatenation.

  Returns:
    a BoxList with number of boxes equal to
      sum([boxlist.num_boxes() for boxlist in BoxList])
  Raises:
    ValueError: if boxlists is invalid (i.e., is not a list, is empty, or
      contains non BoxList objects), or if requested fields are not contained in
      all boxlists
  """
    if not isinstance(boxlists, list):
        raise ValueError("boxlists should be a list")
    if not boxlists:
        raise ValueError("boxlists should have nonzero length")
    for boxlist in boxlists:
        if not isinstance(boxlist, np_box_list.BoxList):
            raise ValueError(
                "all elements of boxlists should be BoxList objects"
            )
    concatenated = np_box_list.BoxList(
        np.vstack([boxlist.get() for boxlist in boxlists])
    )
    if fields is None:
        fields = boxlists[0].get_extra_fields()
    for field in fields:
        first_field_shape = boxlists[0].get_field(field).shape
        first_field_shape = first_field_shape[1:]
        for boxlist in boxlists:
            if not boxlist.has_field(field):
                raise ValueError("boxlist must contain all requested fields")
            field_shape = boxlist.get_field(field).shape
            field_shape = field_shape[1:]
            if field_shape != first_field_shape:
                raise ValueError(
                    "field %s must have same shape for all boxlists "
                    "except for the 0th dimension." % field
                )
        concatenated_field = np.concatenate(
            [boxlist.get_field(field) for boxlist in boxlists], axis=0
        )
        concatenated.add_field(field, concatenated_field)
    return concatenated