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From Kedar Palsule <palsule.ke...@gmail.com>
Subject Re: [math] Re: NormalDistribution
Date Tue, 23 Feb 2010 16:26:37 GMT
Dear Luc,

Thanks for your super fast response. It worked !
Best Regards,
Kedar
On Mon, Feb 22, 2010 at 2:55 PM, Luc Maisonobe <Luc.Maisonobe@free.fr>wrote:

> Kedar Palsule a écrit :
> > Hi Team,
> >
> > I cant figure out how to download the development version 2.1 of Apache
> Math
> > Commons.  Alternatively, it would be good if I could figure out how to
> > download the nightly build.
> > The problem is that the official release, version 2.0, has a bug in a
> part
> > of the code that I need.
> >
> > Please let me knowif I can do either
>
> Since 2.1 is not released yet, you have to download the sources from the
> subversion repository and build it yourself.
>
> Here is a way to do it from the command line in a linux environment:
>
>  svn checkout http://svn.apache.org/repos/asf/commons/proper/math/trunk
>  cd trunk
>  mvn package
>
> Luc
>
> > Best Regards,
> > Kedar
> >
> > On Mon, Feb 22, 2010 at 5:59 AM, kalpa rajadurai <arkalpa@gmail.com>
> wrote:
> >
> >> Hi Team,
> >>
> >> Thanks for your quick response.
> >>
> >> We would like to know, when this bug will be fixed and probably when
> >> Commons
> >> Math 2.1 Version would be released? As our project is dependent on your
> >> API,
> >> it would be highly appreciated if we get the fix or any kind of work
> around
> >> as soon as possible.
> >>
> >> Thanks in advance
> >>
> >> On Sat, Feb 20, 2010 at 8:41 PM, Phil Steitz <phil.steitz@gmail.com>
> >> wrote:
> >>
> >>> kalpa rajadurai wrote:
> >>>> Hi Team,
> >>>>
> >>>> We are working on a small project in designing a web based statistical
> >>>> calculator, supporting certain distribution functions.
> >>>>
> >>>> we used  method *cummulativeProbability(double x)* of *class
> >>>> NormalDistributionImpl* for implementing Normal distribution function.
> >>>>
> >>>> We tried to cross check Apache API's result with that of OpenOffice
> >> Calc
> >>> and
> >>>> Excel's result. In most of the cases, the results matched with each
> >>> other.
> >>>> But in certain rare cases, the cumulativeProbability() method returned
> >> by
> >>>> slightly different result when compared to the result returned by
> >>> NORMDIST()
> >>>> function of openoffice calc and Excel.
> >>>>
> >>>> Here goes the illustration of the case where we found the mismatch in
> >>>> results:
> >>>>
> >>>> *Using Apache's API:*
> >>>> NormalDistribution normDist = new NormalDistributionImpl(40,1.5)
> >>>> ;
> >>>> try{
> >>>> System.out.println("cummulative probability::
> >>>> "+normDist.cumulativeProbability(0.908789));
> >>>> }
> >>>> catch(MathException e){
> >>>> e.printStackTrace();
> >>>> }
> >>>>
> >>>> *Result:*
> >>>> cummulative probability:: *-8.104628079763643E-15*
> >>>>
> >>>> *Using openoffice calc:*
> >>>> Same input values given in openoffice calc using the formula:
> >>>> *=NORMDIST(0.908789;40;1.5;1)*
> >>>>
> >>>> *Result:*
> >>>> *0.0*
> >>>>
> >>>> *Using Microsoft Excel:*
> >>>> Same input values given in excel using the formula:
> >>>> *=NORMDIST(0.908789;40;1.5;1)*
> >>>>
> >>>> *Result:*
> >>>> *5.0738E-150*
> >>>>
> >>>> *Different results:*
> >>>> Apache  -8.104628079763643E-15
> >>>> Openoffice 0.0
> >>>> Excel 5.0738E-150
> >>>>
> >>>> We wish to know the following things,
> >>>> 1.) What is the reason for this variation in results?
> >>> The difference is due to different numeric algorithms used to
> >>> approximate the cumulative probabilities - in particular how extreme
> >>> values are handled.  The probability in the example is very close to
> >>> zero - all three agree on that.
> >>>
> >>>> 2.) Which result is more accurate?
> >>> Excel is likely the best answer; though the only confirmation that I
> >>> can give of that is that R gives the same answer and the correct
> >>> answer is certainly positive.  The worst answer is the one reported
> >>> by commons-math.  The value should not be negative.  This is likely
> >>> related to an open bug (MATH-301).  Thank you for reporting this.
> >>>
> >>>> 3.) Is there any possibility to get the same results as Open Office
or
> >>> Excel
> >>>> for this case, using Apache's API?
> >>> Commons Math 2.1 will correct the bug mentioned above, so we will
> >>> return either 0 or a positive value for this and other extreme tail
> >>> probabilities.
> >>>
> >>> Thanks again for pointing out the discrepancy.
> >>>
> >>> Phil
> >>>
> >>>> Hope to receive reply from your team at the earliest as possible.
> >>>> Thanks in Advance
> >>>>
> >>>
> >>> ---------------------------------------------------------------------
> >>> To unsubscribe, e-mail: user-unsubscribe@commons.apache.org
> >>> For additional commands, e-mail: user-help@commons.apache.org
> >>>
> >>>
> >>
> >> --
> >> Karpaga R
> >>
> >> "Did you always know that?"
> >> "No, I didn't. But I believed"
> >>  ---Matrix III
> >>
> >
>
>
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>
>

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