class_docstr: Class for incrementally computing the variance of a series of numbers.
class_docstr_tok: ["Class","for","incrementally","computing","the","variance","of","a","series","of","numbers","."]
code: def se(self):
      if self.sd is None:
          return None
      return self.sd / sqrt(self.n)
  
imports: from abc import abstractmethod
  from typing import List
  from math import sqrt
  import numpy
label_desc: Use image node_id 8 for calling the Variance obj's underlying member method code with example usage: obj.se() and returns: unknown, None