code: def var(xs):
      """Returns the variance of an iterable.
  
      Example:
  
          >>> var([1, 4, 8, 11])            #doctest:+ELLIPSIS
          19.333333...
  
      @param xs: an iterable yielding numbers.
      @return: the variance of the numbers provided by the iterable.
  
      @see: RunningMean() if you also need the mean
      """
      return RunningMean(xs).var
  
imports: import math
label_desc: Use image node_id 7 for calling a global function with example usage: var(xs) and returns: RunningMean