Analysis of four-point grids: the diamond configuration

Equations for the four-point grid can be derived from data taken in the diamond array. The equations are obtained from analogous equations for the rectangle or by appeal to the shifting operator, <f>exp(x)F(x)=F(x+h)</f>. Curvature on the grid is estimated by interaction and quadratic coefficients. These coefficients compare favorably to the same coefficients as determined by Taylor expansion of the functions generating the data. [Copyright &y& Elsevier]