From what I can tell, the simplest way is to First generate all the combinations Then exclude those you don't want.
Here's an example, with only three variables (D, E, and F), that excludes those where E and F both fail > tmp <- c('p','f') > X <- expand.grid(D=tmp, E=tmp, F=tmp) > X <- subset(X, !(E=='f' & F=='f')) > X D E F 1 p p p 2 f p p 3 p f p 4 f f p 5 p p f 6 f p f -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 Lab cell 925-724-7509 On 8/2/18, 8:41 AM, "R-help on behalf of R Stafford" <r-help-boun...@r-project.org on behalf of rod.staff...@gmail.com> wrote: Thank you for pointing that out, I realize not only did I use the wrong language but I did not describe the situation accurately. I do need to address the situation where both variables E and F actually pass, that is the majority case, one or the other can fail, but there can never be a situation where E and F both fail. I do not know a specific term for that situation, but you are correct that mutual exclusivity is wrong. While I can generate a list of all possible combinations with the expand.grid function (which I am not committed to by the way), it would be very helpful if I could exclude the combinations where E and F both fail. I am not sure where to go from here, but the solution does not have to be elegant or even efficient because I do not need to scale higher than 6 variables. On Thu, Aug 2, 2018 at 7:26 AM, S Ellison <s.elli...@lgcgroup.com> wrote: > > On Thu, Aug 2, 2018 at 11:20 AM, R Stafford <rod.staff...@gmail.com> > > wrote: > > > But I have the extra condition that if E is true, then F must be > false, and > > > vice versa, > > Question: Does 'vice versa' mean > a) "if E is False, F must be True" > or > b) "if F is True, E must be False"? > ... which are not the same. > > b) (and mutual exclusivity in general) does not rule out the condition "E > False, F False", which would not be addressed by the > pass/fail equivalent equivalent of F <- !E > > > > > ******************************************************************* > This email and any attachments are confidential. Any u...{{dropped:13}} ______________________________________________ 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.