Constructing flexible space-filling designs for computer experiments

A computer-implemented method comprising:

• receiving information defining a boundary for a design space;
• generating representative points, each distributed on or within the design space and representing a potential design point for the design space;
• determining for the design space:
• primary clusters, each containing a different set of the representative points that is mutually exclusive of representative points in other primary clusters of the design space;
• a categorical factor, wherein the categorical factor defines a design category for the design space, the design category comprising discrete design options in the design category for the design space;
• and
• at least two levels for the categorical factor, wherein each of the at least two levels defines different ones of the discrete design options in the design category for the design space;
• for each of the primary clusters:
• determining a plurality of sub-clusters, each containing different subsets of a respective set of the representative points that is mutually exclusive of representative points in other sub-clusters of a respective primary cluster of the primary clusters;
• selecting a design point from each sub-cluster of the respective primary cluster based on a first criterion representing separation between design points in the design space;
• and
• allocating the at least two levels of the categorical factor, such that a level of the at least two levels is allocated to each selected design point in the respective primary cluster;
• obtaining an initial sub-design that represents the selected design points in the design space allocated a given level of the categorical factor;
• modifying the initial sub-design by increasing separation between design points allocated a same level of the categorical factor in the design space;
• and
• outputting to an output device a modified design for the design space, wherein the modified design represents locations for obtained design points in the design space in response to modification of the initial sub-design.

A computing device comprising processor and memory, the memory containing instructions executable by the processor wherein the computing device is configured to:

• receive information defining a boundary for a design space;
• generate representative points, each distributed on or within the design space and representing a potential design point for the design space;
• determine for the design space:
• primary clusters, each containing a different set of the representative points that is mutually exclusive of representative points in other primary clusters of the design space;
• a categorical factor, wherein the categorical factor defines a design category for the design space, the design category comprising discrete design options in the design category for the design space;
• and
• at least two levels for the categorical factor, wherein each of the at least two levels defines different ones of the discrete design options in the design category for the design space;
• for each of the primary clusters:
• determine a plurality of sub-clusters, each containing different subsets of a respective set of the representative points that is mutually exclusive of representative points in other sub-clusters of a respective primary cluster of the primary clusters;
• select a design point from each sub-cluster of the respective primary cluster based on a first criterion representing separation between design points in the design space;
• and
• allocate the at least two levels of the categorical factor, such that a level of the at least two levels is allocated to each selected design point in the respective primary cluster;
• obtain an initial sub-design that represents the selected design points in the design space allocated a given level of the categorical factor;
• modify the initial sub-design by increasing separation between design points allocated a same level of the categorical factor in the design space;
• and
• output to an output device a modified design for the design space, wherein the modified design represents locations for obtained design points in the design space in response to modification of the initial sub-design.