Have you gone through any R tutorials? If not, why not? If so, maybe you need to spend some more time with them.
It looks like you want us to do your work for you. We don't do this. See (and follow) the posting guide below for what we might do (we're volunteers, so no guarantees). Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Wed, Jun 21, 2017 at 2:50 PM, Ek Esawi <esaw...@gmail.com> wrote: > I have a data.table which is shown below. I want to count combinations of > columns on i and count on j with by. A few examples are given below the > table. > > > > I want to: > > all months to show on the output including those that they have zero value > > I want the three statements combined in on if possible so the output will > be one data table; that is the outputs are next to each other as manually > illustrated on the last part (desired output). > > > > > > Thanks--EK > > > > > >> Test > > Color Grade Value Month Day > > 1: yellow A 20 May 1 > > 2: green B 25 June 2 > > 3: green A 10 April 3 > > 4: black A 17 August 3 > > 5: red C 5 May 5 > > 6: orange D 0 June 13 > > 7: orange E 12 April 5 > > 8: orange F 11 August 8 > > 9: orange F 99 April 23 > > 10: orange F 70 May 7 > > 11: black A 77 June 11 > > 12: green B 87 August 33 > > 13: black A 79 April 9 > > 14: green A 68 May 14 > > 15: black C 90 June 31 > > 16: green D 79 August 11 > > 17: black E 101 April 17 > > 18: red F 90 June 21 > > 19: red F 112 August 13 > > 20: red F 101 April 20 > >> Test[Color=="green"&Grade=="A", .N, by=Month] > > Month N > > 1: April 1 > > 2: May 1 > >> Test[Color=="orange"&Grade=="F", .N, by=Month] > > Month N > > 1: August 1 > > 2: April 1 > > 3: May 1 > > > >> Test[Color=="orange"&Grade=="F", .N, by=Month] > > Month N > > 1: August 1 > > 2: April 1 > > 3: May 1 > >> Test[Color=="red"&Grade=="F", .N, by=Month] > > Month N > > 1: June 1 > > 2: August 1 > > 3: April 1 > > > > Desired output > > N1 N2 N3 > > April 1 1 1 > > May 1 1 1 > > June 0 0 0 > > August 0 1 1 > > [[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.