7. The method as set forth in claim 6 , wherein the one-dimensional analytical functions are selected from a group consisting of (i) constant functions, (ii) linear functions, and (iii) polynomial functions.
6. The method as set forth in claim 3 , wherein the determining further comprises: for the first dimension of the vector space, approximating the one-dimensional function by a piecewise combination of one-dimensional analytical functions; and repeating the approximating for the one-dimensional functions of the remaining dimensions of the vector space.