Interpolation problem

find a function which passes through (or close to) the given set of discrete points: univariate - curve: y = f(x) bivariate - surface: z = f(x,y) trivariate - volume: w = f(x,y,z) quadvariate - dynamic volume: w = f(x,y,z,t) The problem does not have a unique solution and the character and properties of the interpolation function f(r) depend on additional conditions (statistical, geometrical:smoothnes, locality, physical: minimum energy, etc.)