class_docstr: Mean average precision metric.
docstr: :class:`MeanAveragePrecision` constructor.
  
  :param threshold: The threshold of relevance degree.
docstr_tok: [":","class",":","`","MeanAveragePrecision","`","constructor",".",":","param","threshold",":","The","threshold","of","relevance","degree","."]
code: def __init__(self, threshold: float = 0.0):
      """
      :class:`MeanAveragePrecision` constructor.
  
      :param threshold: The threshold of relevance degree.
      """
      self._threshold = threshold
  
imports: import numpy
  from matchzoo.engine.base_metric import BaseMetric, sort_and_couple
label_desc: Use image node_id 1 to create a new MeanAveragePrecision object from inherited base classes: BaseMetric with example: obj = MeanAveragePrecision(threshold)