# [R] Finding Infimum in R

Boris Steipe boris.steipe at utoronto.ca
Mon Apr 10 10:57:49 CEST 2017

```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
>>>>
>>>> ______________________________________________
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>>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
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