Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
When an injective pseudo-Boolean function f:B^n -> R is minimized, where B^n=0,1^n is the set of vertices of the unit-hypercube, it is natural to consider so-called greedy vertex-following algorithms. These algorithms construct a sequence of neighbouring (Hamming distance 1) vertices with decreasing f-value. The question arises as to when such algorithm will find the global optimum given any starting point. This paper describes a hierarchy of such classes of fonctions that are shown to strictly contain each other. These classes are, in increasing order of generality, the threshold, the saddle-free, the pseudomodular, the completely unimodal, the unimodal, and the unimin (respectively, unimax) functions. Some considerations as to the complexity of the above-mentioned class of algorithm are also made.
Basil Duval, Jonathan Bryan Lister, Jean-Marc Moret, Philippe Marmillod, Xavier Llobet, Blaise Marlétaz, Pierre-François Isoz