Analysis of three-dimensional grids: Alternative methods for five- and nine-point cubes

Equations for the five-point rectangle or diamond arrays represent the first step in the interpolation of particular configurations of measurements in prismatic array. This paper illustrates alternative five-point interpolating equations. The nine-point cube can be interpolated by polynomial equations that are based on an alternative set of quadratic-term coefficients. The equations are easy to apply and they estimate first-, second-, and third-order effects. The accuracies of the estimates rendered by the five- and nine-point equations may be sufficient to interest experimentalists.