[R] Combinations of true/false values where one pair is mutually exclusive

Bert Gunter bgunter@4567 @end|ng |rom gm@||@com
Thu Aug 2 19:11:03 CEST 2018

```Logic:

!(E == "fail" & F == "fail)   <==>

(E == "pass" | F == "pass")

-- 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 Thu, Aug 2, 2018 at 8:57 AM, Sarah Goslee <sarah.goslee using gmail.com> wrote:

> Given that clarification, I'd just generate the full set and remove
> the ones you aren't interested in, as in:
>
>
> scenarios <- expand.grid(A = c("pass", "fail"), B = c("pass", "fail"), C =
> c("pass", "fail"), D = c("pass", "fail"), E = c("pass", "fail"), F =
> c("pass", "fail"))
>
>
> scenarios <- subset(scenarios, !(E == "fail" & F == "fail))
>
> Sarah
>
> On Thu, Aug 2, 2018 at 11:41 AM, R Stafford <rod.stafford using 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
> > 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.Ellison using lgcgroup.com>
> wrote:
> >
> >> > On Thu, Aug 2, 2018 at 11:20 AM, R Stafford <rod.stafford using 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
> >>
> >>
> >>
>
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