Analysis of three-dimensional grids: The cube and the octahedron

The analysis of three-dimensional data is customarily performed by arranging eight measurements in a cubical array and representing them by the trilinear equation. The octahedral design offers the prospect of reduced laboratory costs because it requires only six measurements. Operational interpolating equations for six data in octahedral array can be more accurate than the trilinear equation for eight data in cubical array. The operational equations apply to the six- or seven-point octahedron.