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 Best Regards, Kedar On Mon, Feb 22, 2010 at 5:59 AM, kalpa rajadurai <[email protected]> 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 <[email protected]> > 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: [email protected] > > For additional commands, e-mail: [email protected] > > > > > > > -- > Karpaga R > > "Did you always know that?" > "No, I didn't. But I believed" > ---Matrix III >
