class_docstr: assigner of rbox
  Args:
      pos_iou_thr (float): threshold of pos samples
      neg_iou_thr (float): threshold of neg samples
      min_iou_thr (float): the min threshold of samples
      ignore_iof_thr (int): the ignored threshold
class_docstr_tok: ["assigner","of","rbox","Args",":","pos_iou_thr","(","float",")",":","threshold","of","pos","samples","neg_iou_thr","(","float",")",":","threshold","of","neg","samples","min_iou_thr","(","float",")",":","the","min","threshold","of","samples","ignore_iof_thr","(","int",")",":","the","ignored","threshold"]
code: def __init__(
      self,
      pos_iou_thr=0.5,
      neg_iou_thr=0.4,
      min_iou_thr=0.0,
      ignore_iof_thr=-2,
  ):
      super(RBoxAssigner, self).__init__()
  
      self.pos_iou_thr = pos_iou_thr
      self.neg_iou_thr = neg_iou_thr
      self.min_iou_thr = min_iou_thr
      self.ignore_iof_thr = ignore_iof_thr
  
imports: import sys
  import paddle
  from ppdet.core.workspace import register, serializable
  from .target import rpn_anchor_target, generate_proposal_target, generate_mask_target, libra_generate_proposal_target
  import numpy
label_desc: Use image node_id 1 to create a new RBoxAssigner object from inherited base classes: object with example: obj = RBoxAssigner(pos_iou_thr, neg_iou_thr, min_iou_thr, ignore_iof_thr)