Principal Component Analysis and Higher Correlations for Distributed Data
arXiv:1304.3162
Abstract
We consider algorithmic problems in the setting in which the input data has been partitioned arbitrarily on many servers. The goal is to compute a function of all the data, and the bottleneck is the communication used by the algorithm. We present algorithms for two illustrative problems on massive data sets: (1) computing a low-rank approximation of a matrix , with matrix stored on server and (2) computing a function of a vector , where server has the vector ; this includes the well-studied special case of computing frequency moments and separable functions, as well as higher-order correlations such as the number of subgraphs of a specified type occurring in a graph. For both problems we give algorithms with nearly optimal communication, and in particular the only dependence on , the size of the data, is in the number of bits needed to represent indices and words ().
rewritten with focus on two main results (distributed PCA, higher-order moments and correlations) in the arbitrary partition model