Only closed set is mined. One may generate all combinations themselves
sent from handheld device excuse typos On Mar 18, 2011 7:08 AM, "Vipul Pandey (JIRA)" <[email protected]> wrote: > > [ https://issues.apache.org/jira/browse/MAHOUT-617?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13008276#comment-13008276] > > Vipul Pandey commented on MAHOUT-617: > ------------------------------------- > > Looks like FPGrowth report only the closed sets , is that right? > IN that case I may have to mine for all the frequent subsets manually? > >> FPGrowth/PFPGrowth giving out wrong results. >> --------------------------------------------- >> >> Key: MAHOUT-617 >> URL: https://issues.apache.org/jira/browse/MAHOUT-617 >> Project: Mahout >> Issue Type: Bug >> Components: Frequent Itemset/Association Rule Mining >> Affects Versions: 0.4 >> Environment: Mac OS X, Linux >> Reporter: Vipul Pandey >> Assignee: Robin Anil >> Labels: AssociationMining, FPGrowth, FrequentItemsets >> Attachments: XY, XYZ >> >> >> FPGrowth reports the support of itemsets individually - in that - if Item X appears "individually" 12 times and appears with item Y 10 times (a total of 22 times) AND item Y appears "individually" 4 times (a total of 14 times) then this is what the output will be (say for min-support 2) >> 12 X >> 10 XY >> 4 Y >> Instead of >> 22 X >> 10 XY >> 14 Y >> Also, because of this If the minimum support is 5 then the output will look like : >> 12 X >> 10 X Y >> Thus totally Ignoring Y >> if the minimum support is 11 then the output will look like >> 12 X >> again Ignoring Y >> if the minimum support is 13 then there will be NO output. even though all the way along Xs support was 22 and Y's was 14 >> Even if we want to show just the maximal itemsets (although i would like to see ALL the frequent itemsets - maximal or not) this output is wrong as with a support of 13 we should still have seen X(22) and Y(14) >> Now Say you add XYZ 11 times >> for support 1 you'd see >> 12 X >> 10 X Y >> 11 X Y Z >> 4 Y >> And for support 11 you'd see >> 12 X >> 11 X Y Z >> Although I'd expect the output (for both s=1 & s=11) to be >> 33 X >> 25 Y >> 21 XY >> 11 Z >> 11 XZ >> 11 YZ >> 11 XYZ >> attached are the sample inputs: > > -- > This message is automatically generated by JIRA. > For more information on JIRA, see: http://www.atlassian.com/software/jira
