Use Irregular Grid layout when the X-coordinates of each point or the Y-coordinates of each point are not the same distance apart. The following diagram illustrates the characteristics of Irregular Grid layout:
The important Irregular Grid layout characteristics are:
•The number of rows and columns, the origins, and the irregular grid spacing deltas defines the X/Y grid.
•Each row and column has its own RowDelta / ColumnDelta value that sets the grid spacing between that row/column and the previous one.