class_docstr: Likes :class:`WelfordCovariance` but generalized to the arrowhead structure.
class_docstr_tok: ["Likes",":","class",":","`","WelfordCovariance","`","but","generalized","to","the","arrowhead","structure","."]
code: def __init__(self, head_size=0):
      self.head_size = head_size
      self.reset()
  
file_path: pyro/pyro/ops/welford.py
imports: import torch
label_desc: Use image node_id 1 to create a new WelfordArrowheadCovariance object  with example: obj = WelfordArrowheadCovariance(head_size)