Sorry. typo. it should read " Larger part of *apache-math* is linear algebra, which is currently broken for sparse part of the equation and which we don't use at all."
On Mon, Aug 12, 2013 at 3:26 PM, Dmitriy Lyubimov <dlie...@gmail.com> wrote: > Larger part of apache-math is linear algebra, which is currently broken > for sparse part of the equation and which we don't use at all. > > One part of the problem is that our use for that library is always a > fringe case, and as far as i can tell, will always continue to be such. > > Another part of the problem is that keeping dependency will invite > bypassing Mahout's solvers and, as a result, architecture inconsistency. > > That said, I guess Ted's argument (which is mainly cost, as i gathered), > trumps the two above. > > > On Mon, Aug 12, 2013 at 3:20 PM, Peng Cheng <pc...@uowmail.edu.au> wrote: > >> seriously, I would prefer the dependency as a good architectural pattern. >> It encourages other people to use/contribute to it to avoid repetitive work. >> >> >> On 13-08-12 06:16 PM, Ted Dunning wrote: >> >>> I am fine with it staying. >>> >>> >>> On Mon, Aug 12, 2013 at 3:14 PM, Dmitriy Lyubimov <dlie...@gmail.com> >>> wrote: >>> >>> So you are ok with apache-math dependency to stay? >>>> >>>> >>>> On Mon, Aug 12, 2013 at 3:09 PM, Ted Dunning <ted.dunn...@gmail.com> >>>> wrote: >>>> >>>> So I checked on these. The non-trivial issues with replacing Commons >>>>> >>>> Math >>>> >>>>> include: >>>>> >>>>> - Poisson and negative binomial distributions. This would be several >>>>> >>>> hours >>>> >>>>> work to write and test (we have Colt-inherited negative binomial >>>>> distribution, but it takes no longer to write a new one than to test an >>>>> >>>> old >>>> >>>>> one). >>>>> >>>>> - random number generators. This is about and hour or two of work to >>>>> >>>> pull >>>> >>>>> the MersenneTwister implementation into our code. >>>>> >>>>> - next prime number finder. Not a big deal to replicate, but it would >>>>> >>>> take >>>> >>>>> a few hours to do. >>>>> >>>>> - quadrature. We use an adaptive integration routine to check >>>>> >>>> distribution >>>> >>>>> properties. This, again, would take a few hours to replace. >>>>> >>>>> I really don't see the benefit to this work. >>>>> >>>>> On Mon, Aug 12, 2013 at 2:53 PM, Ted Dunning <ted.dunn...@gmail.com> >>>>> wrote: >>>>> >>>>> 2 distribution.**PoissonDistribution; >>>>>> 2 distribution.**PascalDistribution; >>>>>> 2 distribution.**NormalDistribution; >>>>>> 1 util.FastMath; >>>>>> 1 random.RandomGenerator; >>>>>> 1 random.MersenneTwister; >>>>>> 1 primes.Primes; >>>>>> 1 linear.RealMatrix; >>>>>> 1 linear.EigenDecomposition; >>>>>> 1 linear.Array2DRowRealMatrix; >>>>>> 1 distribution.RealDistribution; >>>>>> 1 distribution.**IntegerDistribution; >>>>>> 1 analysis.integration.**UnivariateIntegrator; >>>>>> 1 analysis.integration.**RombergIntegrator; >>>>>> 1 analysis.UnivariateFunction; >>>>>> >>>>>> >> >> >
