Lacking any reference to R, this message is off-topic on this mailing list. You might try math.stackexchange.com. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity.
On May 3, 2015 8:36:29 AM PDT, Dany <daniela_sc...@brown.edu> wrote: >Hi I saw the answer: > >�If the graph has n nodes and is represented by an adjacency matrix, >you can square the matrix (log_2 n)+1 times. Then you can multiply the >matrix element-wise by its transpose. � > >I�m a PhD student working on my research and I need to check for cycles >in a directed graph to make sure it is a DAG. The answer given is >extremely useful but I need the theorem statement, or a reference. Do >you have a book where this is stated or a paper? > >Thanks! > >Daniela. > [[alternative HTML version deleted]] > > > >------------------------------------------------------------------------ > >______________________________________________ >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >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 -- To UNSUBSCRIBE and more, see 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.