Size function
（重定向自Measuring function）
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Size functions are shape descriptors, in a geometrical/topological sense. They are functions from the half-plane ![x<y\](/Images/godic/202501/26/cf3904572b42c571060f5cea160eb9901337.png")
to the natural numbers, counting certain connected components of a topological space. They are used in pattern recognition and topology.