On Wed, Sep 24, 2014 at 9:15 PM, Saikat Kanjilal <sxk1...@hotmail.com> wrote:
> Shannon/Dmitry,Quick question, I'm wanting to calculate the scala > equivalent of the frobenius norm per this API spec in python ( > http://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.norm.html), > I dug into the mahout-math-scala project and found the following API to > calculate the norm: > > > > > > > > > def norm = sqrt(m.aggregate(Functions.PLUS, Functions.SQUARE)) > I believe the above is also calculating the frobenius norm, however I am > curious why we are calling a Java API from scala, the type of m above is a > java interface called Matrix, I'm guessing the implementation of aggregate > is happening in the math-math-scala somewhere, is that assumption correct? > We are colling Colt (i.e. java) for pretty much everything. As far as scala bindings are concerned, they are but a DSL wrapper to Colt (unlike distributed algebra which is much more). Aggregate is Colt's thing. Colt (aka Mahout-math) establish java-side concept of different function types which are unfortunately not compatible with Scala literals. > Thanks in advance. > > From: sxk1...@hotmail.com > > To: dev@mahout.apache.org > > Subject: RE: Mahout-1539-computation of gaussian kernel between 2 arrays > of shapes > > Date: Thu, 18 Sep 2014 12:51:36 -0700 > > > > Ok great I'll use the cartesian spark API call, so what I'd still like > some thoughts on where the code that calls the cartesian should live in our > directory structure. > > > Date: Thu, 18 Sep 2014 15:33:59 -0400 > > > From: squ...@gatech.edu > > > To: dev@mahout.apache.org > > > Subject: Re: Mahout-1539-computation of gaussian kernel between 2 > arrays of shapes > > > > > > Saikat, > > > > > > Spark has the cartesian() method that will align all pairs of points; > > > that's the nontrivial part of determining an RBF kernel. After that > it's > > > a simple matter of performing the equation that's given on the > > > scikit-learn doc page. > > > > > > However, like you said it'll also have to be implemented using the > > > Mahout DSL. I can envision that users would like to compute pairwise > > > metrics for a lot more than just RBF kernels (pairwise Euclidean > > > distance, etc), so my guess would be a DSL implementation of > cartesian() > > > is what you're looking for. You can build the other methods on top of > that. > > > > > > Correct me if I'm wrong. > > > > > > Shannon > > > > > > On 9/18/14, 3:28 PM, Saikat Kanjilal wrote: > > > > > http://scikit-learn.org/stable/modules/generated/sklearn.metrics.pairwise.rbf_kernel.html > > > > I need to implement the above in the scala world and expose a DSL > API to call the computation when computing the affinity matrix. > > > > > > > >> From: ted.dunn...@gmail.com > > > >> Date: Thu, 18 Sep 2014 10:04:34 -0700 > > > >> Subject: Re: Mahout-1539-computation of gaussian kernel between 2 > arrays of shapes > > > >> To: dev@mahout.apache.org > > > >> > > > >> There are number of non-traditional linear algebra operations like > this > > > >> that are important to implement. > > > >> > > > >> Can you describe what you intend to do so that we can discuss the > shape of > > > >> the API and computation? > > > >> > > > >> > > > >> > > > >> On Wed, Sep 17, 2014 at 9:28 PM, Saikat Kanjilal < > sxk1...@hotmail.com> > > > >> wrote: > > > >> > > > >>> Dmitry et al,As part of the above JIRA I need to calculate the > gaussian > > > >>> kernel between 2 shapes, I looked through mahout-math-scala and > didnt see > > > >>> anything to do this, any objections to me adding some code under > > > >>> scalabindings to do this? > > > >>> Thanks in advance. > > > > > > > > > > >
