P(tag1 and tag2)/[P(tag1) P(tag2)] for 256 most popular tags, see http://bit.ly/map-of-so
Q&A about the site for builders and users of networked sensors and control devices in the contexts of smart homes, industry automation, or environmental sensors
-- for plots like this one: -- http://bit.ly/map-of-so -- P(tag1 and tag2)/[P(tag1) P(tag2)] is -- #tag1tag2 #questions / (#tag1 #tag2) WITH TagCounts AS ( SELECT TOP 256 T.TagName Tag, count(*) TagCount FROM Posts P INNER JOIN PostTags PT ON PT.PostId = P.Id INNER JOIN Tags T ON T.Id = PT.TagId WHERE P.PostTypeId = 1 -- only questions GROUP BY T.TagName --ORDER BY -- TagCount DESC ), TagPairCounts AS ( SELECT T1.TagName Tag1, T2.TagName Tag2, count(*) TagPairCount FROM Posts P INNER JOIN PostTags PT1 ON PT1.PostId = P.Id INNER JOIN PostTags PT2 ON PT2.PostId = P.Id INNER JOIN Tags T1 ON T1.Id = PT1.TagId INNER JOIN Tags T2 ON T2.Id = PT2.TagId WHERE T1.TagName < T2.TagName GROUP BY T1.TagName, T2.TagName --ORDER BY -- TagPairCount DESC ) SELECT TOP 10 TPC.Tag1 FROM TagPairCounts TPC