--- "Mark R. Diggory" <[EMAIL PROTECTED]> wrote: > Al Chou wrote: > > >--- [EMAIL PROTECTED] wrote: > > > > > >>mdiggory 2003/06/16 07:29:31 > >> > >> Modified: math/xdocs developers.xml > >> math/src/java/org/apache/commons/math/stat > >> UnivariateImpl.java > >> math/src/test/org/apache/commons/math/stat > >> CertifiedDataTest.java > >> Log: > >> PR: http://nagoya.apache.org/bugzilla/show_bug.cgi?id=20782 > >> Submitted by: [EMAIL PROTECTED] > >> > >> I added this, but there are changes I'd like to make in the near future. > >>Only the "running" aspects of the variance calc should be in the > insertValue > >>function, all other calculation should be in the getVariance function. > >> > >> > > > >OK, that sounds reasonable. Also, I was starting an Extract Method > refactoring > >to reduce duplication among the windowSize != n and infinite window branches > of > >insertValue. > > > > > >Al > > > > Yes, this is the direction I am working on as well. Lets try to > coordinate our efforts. > > (1) I'm looking to setup "true deligation" where UnivariateImpl is > actually an extension of AbstractStoreUnivariate and deligates to these > methods when doing stored processing. This would simply look like: > > /** > * @see org.apache.commons.math.stat.Univariate#getMean() > */ > public double getMean() { > if (windowSize != Univariate.INFINITE_WINDOW) { > return super.getMean(); > } > > return mean; > }
-1 I would prefer for both to delegate to an optimized method in StatUtils. > > (2) I want to apply the same strategy used in your mean and variance > calculations for skew and kurt. The getters for these properties then > would truely just be "getters" without the calculations occuring in them > as well. This means the sum of powers code goes away for now. > > (3) I want to derive an methodology for the same two-pass algorithm for > skew and kurt, hey, if we can't find published work on it, then theres a > possibly paper in the future for someone to write! > We should stick with established algorithms. I would suggest researching established computational formulas for higher order moments. > -Mark > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > __________________________________ Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
