Hi Rahul, I didn't have an id, so I created one now. My id is : Aditya Nain
Thanks, Aditya On Mon, Mar 28, 2016 at 6:40 PM, Rahul Iyer <ri...@pivotal.io> wrote: > I can assign this to you, but you need to have an account in > https://issues.apache.org. > If you already have an account, then please send your id - I wasn't able to > find you just using your name. > > On Mon, Mar 28, 2016 at 3:31 PM, Aditya Nain <adityana...@gmail.com> > wrote: > > > Hi Rahul, > > > > Thanks for the reply! > > > > I am working on implementing Gaussian Mixture Model assuming that the > > co-variance matrix is same for all the Gaussians. > > The JIRA which deals GMM is MADBLIB-410: > > > https://issues.apache.org/jira/browse/MADLIB-410?jql=project%20%3D%20MADLIB > > > > Can this be assigned to me, or how do I get it assigned to me? > > > > Thanks, > > Aditya > > > > On Mon, Mar 21, 2016 at 3:41 PM, Rahul Iyer <ri...@pivotal.io> wrote: > > > > > Hi Aditya, > > > > > > Welcome to the MADlib community! > > > > > > Gaussian Mixture models is extrememly useful and we would heartily > > welcome > > > a contribution for it. The SQLEM paper might be oversimplifying the > > > capabilities of the database (e.g. assuming there is no array type is > > > unnecessary for Postgresql). You could speed things (both dev time and > > > execution time) by writing some of the functions in C++. K-means is an > > > example of how clustering is implemented. > > > IMO, assuming the same covariance matrix is reasonable. We could extend > > the > > > capabilities after the initial implementation is complete. > > > > > > There was some work started a long time ago that built perceptrons > using > > > the convex framework (link <https://github.com/iyerr3/madlib/tree/mlp > >). > > > There are still some bugs in that code since the trained network isn't > > > converging. You could start there or build a new module - either ways > an > > > MLP module is frequently demanded by the data science community. > > > > > > I would suggest starting with Gaussian mixtures and then moving to > > > perceptrons if GMM work is completed. > > > > > > Feel free to ask questions on this forum. Looking forward to > > collaborating > > > with you. > > > > > > Best, > > > Rahul > > > > > > On Thu, Mar 17, 2016 at 2:08 PM, Aditya Nain <adityana...@gmail.com> > > > wrote: > > > > > > > Hi, > > > > > > > > My name is Aditya Nain, and I am a graduate student at University of > > > > Florida. > > > > I have been learning MADLib for a while and want to contribute to > > MADLib. > > > > I went through some of the open stories in JIRA and started working > on > > > > MADLIB-410 : > > > > > > > > > > > > > > https://issues.apache.org/jira/browse/MADLIB-410?jql=project%20%3D%20MADLIB > > > > > > > > which is about implementing Gaussian Mixture Model using Expectation > > > > Maximization (EM) algorithm. > > > > > > > > I came across the following paper while searching for distributed EM > > > > algorithm which can be implemented in MADLib. > > > > > > > > Carlos Ordonez, Paul Cereghini "SQLEM: fast clustering in SQL using > the > > > EM > > > > algorithm" ACM SIGMOD Record, Volume 29 Issue 2, June 2000 Pages > > 559-570. > > > > http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.28.7564 > > > > > > > > I thought of implementing the approach discussed in the paper, but > the > > > > paper makes an assumption that the covariance martix is the same for > > all > > > > the clusters ( i.e covariance matrix is same for all the Gaussian > > > > distributions). So, I wanted to know the opinion of the community if > > it's > > > > fine to go with the assumption made in the paper and implement it in > > > > MADLib. > > > > > > > > Also, currently MADLib doesn't have an implementation of a > perceptron, > > > nor > > > > did I find any open story related to it in JIRA. I came across the > > > > following paper, which talks about a distributed algorithm for > > > perceptron : > > > > > > > > Ryan McDonald, Keith Hall, Gideon Mann "Distributed training > strategies > > > for > > > > the structured perceptron" > > > > http://dl.acm.org/citation.cfm?id=1858068 > > > > > > > > Would it useful to have a distributed implementaion of perceptron in > > > > MADlib? > > > > > > > > Thanks, > > > > Aditya > > > > > > > > > >
