code: def sparse_var(X):
      '''
      Compute variance from
      :param X:
      :return:
      '''
      Xc = X.copy()
      Xc.data **= 2
      return np.array(Xc.mean(axis=0) - np.power(X.mean(axis=0), 2))[0f sparse_var(X):
      '''
      Compute variance from
      :param X:
      :return:
      '''
      Xc = X.copy()
      Xc.data **= 2
      return np.array(Xc.mean(axis=0) - np.power(X.mean(axis=0), 2))[0]
docs: Compute variance from
      :param X:
      :return: