LocationsInGrid


superclasses:

CellularStructure

attributes:

gridGrid

locationsMultiset(GridLocation)

comments:

One or more locations in a grid may be referenced (i) through the grid coordinates, (ii) by providing one or more morton numbers, or (iii) by providing a set of mask values, i.e. 0s and 1s, corresponding to the locations in the grid.

The assignment of the locations in the grid is dependent upon the value for grid.orderAndOrigin.originCorner. Consider the following two cases: If the value for this attribute is nw, then the location with the smallest coordinate values, typically (1,1) or (0,0), is assumed to be the upper left corner. If a morton number is provided, the basic quad tree structure is assume to be based on 1 in the upper left, 2 in the upper right, 3 in the lower left, and 4 in the lower right.

If the value for this attribute is sw, then the location with the smallest coordinate values is assumed to be the lower left corner. If a morton number is provided, the basic quad tree structure is assume to be based on 1 in the lower left, 2 in the lower right, 3 in the upper left, and 4 in the upper right.

A similar situation holds if three or four dimensions are considered.


Links to Section 3.2 and the complete SAIF class list