•There are two
ways to ask the similarity question
–How alike are A
and B (symmetric)
–How like is A to B (asymmetric)
•Asymmetric
similarity has the idea of a prototype.
–We may ask how
like is the UK to the USA (prototype)
•In the chemical
world this corresponds to similarity as a superstructure or as a substructure.
•Daylight has
implemented this via the Tversky coefficient where a and b are adjustable parameters to reduce the
effect of the unique bits
•
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