1Blurb:: 2Enforce minimum Euclidean distance between designs 3Description:: 4Currently, the only niche pressure operators available are the \c 5radial nicher, the \c distance nicher, and the \c max_designs nicher. 6The \c radial niche pressure applicator works by enforcing a minimum 7Euclidean distance between designs in the performance space at each 8generation. The algorithm proceeds by starting at the (or one of the) 9extreme designs along objective dimension 0 and marching through the 10population removing all designs that are too close to the current 11design. One exception to the rule is that the algorithm will never 12remove an extreme design which is defined as a design that is maximal 13or minimal in all but 1 objective dimension (for a classical 2 14objective problem, the extreme designs are those at the tips of the 15non-dominated frontier). The \c distance nicher enforces a minimimum 16distance in each dimension. 17 18The designs that are removed by the nicher are not discarded. They 19are buffered and re-inserted into the population during the next 20pre-selection operation. This way, the selector is still the only 21operator that discards designs and the algorithm will not waste time 22"re-filling" gaps created by the nicher. 23 24Topics:: 25Examples:: 26Theory:: 27Faq:: 28See_Also:: 29