[R] Finding Infimum in R

Bert Gunter bgunter.4567 at gmail.com
Mon Apr 10 16:38:29 CEST 2017


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.steipe at 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.4567 at 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.hlx at 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.4567 at 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.hlx at 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 at 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 at 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.
>



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