code: def unskew_S1(S1, M, N):
      """
      Unskew the sensitivity indices
      (Jean-Yves Tissot, Clémentine Prieur (2012) "Bias correction for the
      estimation of sensitivity indices based on random balance designs.",
      Reliability Engineering and System Safety, Elsevier, 107, 205-213.
      doi:10.1016/j.ress.2012.06.010)
      """
      lamb = (2 * M) / N
      return S1 - lamb / (1 - lamb) * (1 - S1)
  
file_path: SALib/src/SALib/analyze/rbd_fast.py
imports: import numpy
  from scipy.signal import periodogram
  from scipy.stats import norm
  from .None import common_args
  from ..util import read_param_file, ResultDict
label_desc: Use image node_id 4 for calling a global function with example usage: unskew_S1(S1, M, N) and returns: unknown