domain decomposition; finite elements; sparse matrices; balancing domain decomposition by constrains method; interface weights; averaging operator
Different choices of the averaging operator within the BDDC method are compared on a series of 2D experiments.
Subdomains with irregular interface and with jumps in material coefficients are included into the study. Two new approaches are studied along three standard choices. No approach is shown to be universally superior to others, and the resulting recommendation is that an actual method should be chosen based on properties of the problem.