class_docstr: Create a FisherSnedecor distribution object, often known as F distribution.
  
  Parameters
  ----------
  df1 : Tensor or scalar
      degree of freedom parameter 1
  scale : Tensor or scalar
      degree of freedom parameter 2
class_docstr_tok: ["Create","a","FisherSnedecor","distribution","object",",","often","known","as","F","distribution",".","Parameters","--","--","--","--","--","df1",":","Tensor","or","scalar","degree","of","freedom","parameter","1","scale",":","Tensor","or","scalar","degree","of","freedom","parameter","2"]
code: def mean(self):
      # mean is only defined for df2 > 2
      df2 = np.where(self.df2 <= 2, nan, self.df2)
      return df2 / (df2 - 2)
  
file_path: mxnet/python/mxnet/gluon/probability/distributions/fishersnedecor.py
imports: from numpy import nan
  from .distribution import Distribution
  from .gamma import Gamma
  from .constraint import Positive
  from .utils import gammaln
  from ....None import np
label_desc: Use image node_id 3 for calling the FisherSnedecor obj's underlying member method code with example usage: obj.mean() and returns: unknown