arXiv subjects

Gurinder Singh Atwal

Publications and source records attributed to Gurinder Singh Atwal.

3 recordsLinked to original sources

arXiv2005

Ambiguous model learning made unambiguous with 1/f priors

What happens to the optimal interpretation of noisy data when there exists more than one equally plausible interpretation of the data? In a Bayesian model-learning framework the answer depends on the prior expectations of the dynamics of the model parameter that is to be inferred from the data. Local time constraints on the priors are insufficient to pick one interpretation over another. On the other hand, nonlocal time constraints, induced by a $1/f$ noise spectrum of the priors, is shown to permit learning of a specific model parameter even when there are infinitely many equally plausible interpretations of the data. This transition is inferred by a remarkable mapping of the model estimation problem to a dissipative physical system, allowing the use of powerful statistical mechanical methods to uncover the transition from indeterminate to determinate model learning.

q-bio.OT↗

arXiv2005

Information based clustering

In an age of increasingly large data sets, investigators in many different disciplines have turned to clustering as a tool for data analysis and exploration. Existing clustering methods, however, typically depend on several nontrivial assumptions about the structure of data. Here we reformulate the clustering problem from an information theoretic perspective which avoids many of these assumptions. In particular, our formulation obviates the need for defining a cluster "prototype", does not require an a priori similarity metric, is invariant to changes in the representation of the data, and naturally captures non-linear relations. We apply this approach to different domains and find that it consistently produces clusters that are more coherent than those extracted by existing algorithms. Finally, our approach provides a way of clustering based on collective notions of similarity rather than the traditional pairwise measures.

q-bio.QM↗

arXiv2005

Information based clustering: Supplementary material

This technical report provides the supplementary material for a paper entitled "Information based clustering", to appear shortly in Proceedings of the National Academy of Sciences (USA). In Section I we present in detail the iterative clustering algorithm used in our experiments and in Section II we describe the validation scheme used to determine the statistical significance of our results. Then in subsequent sections we provide all the experimental results for three very different applications: the response of gene expression in yeast to different forms of environmental stress, the dynamics of stock prices in the Standard and Poor's 500, and viewer ratings of popular movies. In particular, we highlight some of the results that seem to deserve special attention. All the experimental results and relevant code, including a freely available web application, can be found at http://www.genomics.princeton.edu/biophysics-theory .

q-bio.QM↗