Er, 1/3, of course? (assuming that F is f). The infimum of a set is not necessarily a member of the set.
-pd > On 10 Apr 2017, at 16:56 , Boris Steipe <boris.ste...@utoronto.ca> wrote: > > Well - the _procedure_ will give a result. > > But think of f(x) = {-1; x <= 1/3 and 1; x > 1/3 > > What should inf{x| F(x) >= 0} be? > What should the procedure return? > > > > > >> On Apr 10, 2017, at 10:38 AM, Bert Gunter <bgunter.4...@gmail.com> wrote: >> >> Given what she said, how does the procedure I suggested fail? >> >> (Always happy to be corrected). >> >> -- 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 Mon, Apr 10, 2017 at 1:57 AM, Boris Steipe <boris.ste...@utoronto.ca> >> wrote: >>> Are you sure this is trivial? I have the impression the combination of an >>> ill-posed problem and digital representation of numbers might just create >>> the illusion that is so. >>> >>> B. >>> >>> >>> >>> >>>> On Apr 10, 2017, at 12:34 AM, Bert Gunter <bgunter.4...@gmail.com> wrote: >>>> >>>> Then it's trivial. Check values at the discontinuities and find the >>>> first where it's <0 at the left discontinuity and >0 at the right, if >>>> such exists. Then just use zero finding on that interval (or fit a >>>> line if everything's linear). If none exists, then just find the first >>>> discontinuity where it's > 0. >>>> >>>> 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 Sun, Apr 9, 2017 at 5:38 PM, li li <hannah....@gmail.com> wrote: >>>>> Hi Burt, >>>>> Yes, the function is monotone increasing and points of discontinuity are >>>>> all known. >>>>> They are all numbers between 0 and 1. Thanks very much! >>>>> Hanna >>>>> >>>>> >>>>> 2017-04-09 16:55 GMT-04:00 Bert Gunter <bgunter.4...@gmail.com>: >>>>>> >>>>>> Details matter! >>>>>> >>>>>> 1. Are the points of discontinuity known? This is critical. >>>>>> >>>>>> 2. Can we assume monotonic increasing, as is shown? >>>>>> >>>>>> >>>>>> -- 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 Sun, Apr 9, 2017 at 1:28 PM, li li <hannah....@gmail.com> wrote: >>>>>>> Dear all, >>>>>>> For a piecewise function F similar to the attached graph, I would like >>>>>>> to >>>>>>> find >>>>>>> inf{x| F(x) >=0}. >>>>>>> >>>>>>> >>>>>>> I tried to uniroot. It does not seem to work. Any suggestions? >>>>>>> Thank you very much!! >>>>>>> Hanna >>>>>>> >>>>>>> ______________________________________________ >>>>>>> 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. >>> > > ______________________________________________ > 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. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.