class_docstr: OksCost.
  
  this function based on: https://github.com/hikvision-research/opera/blob/main/opera/core/bbox/match_costs/match_cost.py
  
  Args:
      num_keypoints (int): number of keypoints
      weight (int | float, optional): loss_weight.
class_docstr_tok: ["OksCost",".","this","function","based","on",":","https",":","\/\/github.com\/hikvision-research\/opera\/blob\/main\/opera\/core\/bbox\/match_costs\/match_cost.py","Args",":","num_keypoints","(","int",")",":","number","of","keypoints","weight","(","int","|","float",",","optional",")",":","loss_weight","."]
code: def __init__(self, num_keypoints=17, weight=1.0):
      self.weight = weight
      if num_keypoints == 17:
          self.sigmas = (
              np.array(
                  [
                      0.26,
                      0.25,
                      0.25,
                      0.35,
                      0.35,
                      0.79,
                      0.79,
                      0.72,
                      0.72,
                      0.62,
                      0.62,
                      1.07,
                      1.07,
                      0.87,
                      0.87,
                      0.89,
                      0.89,
                  ],
                  dtype=np.float32,
              )
              / 10.0
          )
      elif num_keypoints == 14:
          self.sigmas = (
              np.array(
                  [
                      0.79,
                      0.79,
                      0.72,
                      0.72,
                      0.62,
                      0.62,
                      1.07,
                      1.07,
                      0.87,
                      0.87,
                      0.89,
                      0.89,
                      0.79,
                      0.79,
                  ],
                  dtype=np.float32,
              )
              / 10.0
          )
      else:
          raise ValueError(
              f"Unsupported keypoints number {num_keypoints}"
          )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import paddle
  import paddle.nn.functional
  from ppdet.core.workspace import register
label_desc: Use image node_id 1 to create a new OksCost object from inherited base classes: object with example: obj = OksCost(num_keypoints, weight)