Nacionalni portal odprte znanosti

A sketch of a matrix A is another matrix B which is significantly smaller than A but still approximates it well. Finding such sketches efficiently is an important building block in modern algorithms for approximating, for example, the PCA of massive matrices. This task is made more challenging in th ...

This paper revisits the online PCA problem. Given a stream of $n$ vectors $x_t \in \R^d$ (columns of $X$) the algorithm must output $y_t \in \R^\ell$ (columns of $Y$) before receiving $x_{t+1}$. The goal of online PCA is to simultaneously minimize the target dimension $\ell$ and the error $\|X - (XY ...

Correlation clustering is arguably the most natural formulation of clustering. Given a set of objects and a pairwise similarity measure between them, the goal is to cluster the objects so that, to the best possible extent, similar objects are put in the same cluster and dissimilar objects are put in ...