If you read ?dist, it says that: binary: (aka asymmetric binary): The vectors are regarded as binary bits, so non-zero elements are ‘on’ and zero elements are ‘off’. The distance is the proportion of bits in which only one is on amongst those in which at least one is on.
The short answer is that this is the Jaccard Distance measure. If we label the cells of a 2x2 presence absence matrix as a, b, c, d: Present Absent Present a b Absent c d Then the Jaccard Similarity index is a/(a+b+c) And the Jaccard Distance index is (1 - a/(a+b+c)) or (b+c)/(a+b+c) ------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of ?? Sent: Thursday, July 18, 2013 9:56 AM To: r-help@r-project.org Subject: [R] binary distance measure of the "dist" function in the "stats" package Dear all: I want to ask question about "binary" distance measure. As far as I know, there are many binary distance measures,eg, binary Jarcad distance, binary euclidean distance, and binary Bray-Curtis distance,etc. It is even more confusing because many have more than one name. So , I wan to know what the definite name of the binary distance measure of the "dist" function in the "stats" package is and further want to know the equation of the binary distance. Thank you very much! With my best regards. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.