Here is a *proposed* ordering for the task list, with a little commentary added.
One thing that I want to make *very* clear up front, is that I *never* intended the task list or the items listed in the scope section of the proposal to be definitive. All that is definitive are the guiding principles, which just try to keep us focused on stuff that people will find both useful and easy to use. I expected that the actual contents of the first release would include some things not on the list and would exclude some of the things there. At this stage, as Jouzas pointed out, it is more important for us to build community than to rush a release out the door. So if there are things that fit the guidelines that others would like to contribute, but which are not on the list, *please* suggest them. Also, for those who may not have dug into the code, but who may be interested in contributing, please rest assured that deep mathematical knowledge is not required to help. We can review implementations and deal with mathematical problems as they arise, using our small but growing community as a resource. The same is obviously true on the the Java/OS tools side -- no need to be an expert to contribute. OK, long-winded disclaimer aside, here is how I see the task list ordered: * The RealMatrixImpl class is missing some key method implementations. The critical thing is solution of linear systems. We need to implement a numerically sound solution algorithm. This will enable inverse() and also support general linear regression. -- I think that Brent is working on this. * Improve numerical accuracy of Univariate and BivariateRegression statistical computations. Encapsulate basic double[] |-> double mean, variance, min, max computations using improved formulas and add these to MathUtils. (probably should add float[], int[], long[] versions as well.) Then refactor all univariate implementations that use stored values (including UnivariateImpl with finite window) to use the improved versions. -- Mark? I am chasing down the TAS reference to document the source of the _NR_ formula, which I will add to the docs if someone else does the implementation. * Define full package structure and develop user's guide following the package structure. I have started work on the user's guide, but found this impossible without the package structure defined. I will post a separate message summarizing what has been proposed up to now and making a recommendation. * t-test statistic needs to be added and we should probably add the capability of actually performing t- and chi-square tests at fixed significance levels (.1, .05, .01, .001). -- This is virtually done, just need to define a nice, convenient interface for doing one- and two-tailed tests. Thanks to Brent, we can actually support user-supplied significance levels (next item) * numerical approximation of the t- and chi-square distributions to enable user-supplied significance levels. See above. Someone just needs to put a fork in this. Tim? Brent? * *new* add support for F distribution and F test, so that we can report signinficance level of correlation coefficient in bivariate regression / signinficance of model. I will do this if no one else wants to. * Framework and implementation strategie(s) for finding roots or real-valued functions of one (real) variable. Here again -- largely done. I would prefer to wait until J gets back and let him submit his framework and R. Brent's algorithm. Then "our" Brent's implementation and usage can be integrated (actually not much to do, from the looks of the current code) and I will add my "bean equations" stuff (in progress). * Extend distribution framework to support discrete distributions and implement binomial and hypergeometric distributions. I will do this if no one else wants to. If someone else does it, you should make sure to use the log binomials in computations. * Exponential growth and decay (set up for financial applications) I think this is just going to be a matter of finding the right formulas to add to MathUtils. I don't want to get carried away with financial computations, but some simple, commonly used formulas would be a nice addition to the package. We should also be thinking about other things to add to MathUtils -- religiously adhering to th guiding principles, of course. Al's sign() is an excellent example of the kind of thing that we should be adding, IMHO. * Polynomial Interpolation -- let Al tell us what to do here. Even better, let Al do it (he he). * Javadoc generation currently throws 35 warnings. Bring the Javadoc into compliance (i.e. reach zero warnings). A community effort :-) * Clover tests show lots of gaps in test path coverage. Get all tests to 100% coverage * CheckStyle with modified properties still shows many errors. Clean these up. * ComplexNumber implementation, supporting C9x Annex G spec. I would prefer to wait on this, but I could be persuaded to finish my implementation (or better, include someone else's fully compliant implementation) if others feel strongly. * Addition of a Arithmetic Geometric Mean. I would wait in this as well. --------------------------------------------- My proposal for the first release is that we 1) complete the tasks above, other than the last two 2) step back and take a critical look at the design decisions that we have made up to now and consider refactoring some things (Univariate world, RealMatrix, and TestStatistic, esp.) Also obviously finalize package structure. This task obviously needs to run concurrently with the ones above. 3) develop the user's guide and validate all algorithms and documentation. 4) do some performance testing and as much numerical stability validation as we can. 5) follow the Jakarta sandbox process for alpha release Phil __________________________________ Do you Yahoo!? Yahoo! Calendar - Free online calendar with sync to Outlook(TM). http://calendar.yahoo.com --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
