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From Luc Maisonobe <Luc.Maison...@free.fr>
Subject Re: [Math] Toward releasing 3.0 ?
Date Sat, 28 Jan 2012 11:24:05 GMT
Le 27/01/2012 20:44, Sébastien Brisard a écrit :
> Hi Luc,
> thanks for this answer.
>>>
>>> My problem is that I do not know what getSolverAbsoluteAccuracy()
>>> should return. I see three options
>>> 1. Have getSolverAbsoluteAccuracy() throw an
>>> UnsupportedOperationException, as the solver is *never* invoked.
>>> 2. Return a default value, and specify in the Javadoc that it is
>>> meaningless or not really meaningful ;).
>>> 3. Return an estimate of the absolute accuracy of the explicit above
>>> expressions, namely a + FastMath.sqrt(p * (b - a) * (c - a)) and b -
>>> FastMath.sqrt((1 - p) * (b - a) * (b - c)).
>>>
>>> My preferred option is 1. I dislike option 2, because users might
>>> actually be using the returned value, believing it to somehow reflect
>>> the accuracy of the value returned by
>>> inverseCumulativeProbability(double). Option 3 would be a good
>>> compromise, but I certainly do not have the level of expertise to come
>>> up with this estimate... Any help would be most welcome!
>>
>> I don't like UnsupportedOperationException.
>>
> Fine.
>> In this case, I would say
>> the explicit formula is some kind of "perfect" solver
> I agree
>>
>> which has a
>> theoretical accuracy of zero (or 1 ulp). So I would return this value.
>>
> Yes, but one ulp of which number? What I have implemented so far is
> return Math.ulp(c) (the intermediate value). I sould probably return
> Math.max(Math.ulp(a), Math.ulp(b)), what do you think?

Both are fine.

Luc

> Sébastien
> 
> 
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