Editing Sensitivity analysis (section)

=== Chaos polynomials ===
The principle is to project the function of interest onto a basis of orthogonal polynomials. The Sobol indices are then expressed analytically in terms of the coefficients of this decomposition.<ref name="GSA Sudret">{{cite journal |last1=Sudret|first1=B.
|year= 2008
|title=Global sensitivity analysis using polynomial chaos expansions
|url= http://www.sciencedirect.com/science/article/pii/S0951832007001329
|journal=Bayesian Networks in Dependability] 
|volume=93
|issue=7 
|pages=964–979|doi=10.1016/j.ress.2007.04.002
}}</ref>