“…The first stage of approximation can be carried out using (i) linear interpolation algorithms based on triangulation, (ii) inverse distance weighting or polynomial methods, (iii) basis function approach, (iv) Kriging interpolation, (v) piecewise linear function, and (vi) component-wise splines [ 43 , 44 , 45 , 46 , 47 , 48 ]. Each of these methods has both advantages and drawbacks.…”