Calculate logarithmic values for X and Y first, and then perform XYZ Gridding. Gridding methods convert XYZ data into a matrix using a selected algorithm. One common workbook data arrangement - particularly for Excel users - is for X and Y measurements to be stored in the first row and first column of the worksheet, with Z values stored in cells at the intersection of each XY data pair. There are two basic types of worksheet to matrix conversions in Origin: This section explains Origin's gridding options. The resulting matrix of Z values was used to create the contour or 3D surface. Prior to that release, creating these plot types in Origin required gridding of worksheet data. Origin 9.0 introduced 3D surface or contour plotting directly from XYZ worksheet columns or from a Virtual Matrix.