{ "id": "1410.6089", "version": "v1", "published": "2014-10-22T16:02:54.000Z", "updated": "2014-10-22T16:02:54.000Z", "title": "Low-rank approximation of tensors", "authors": [ "Shmuel Friedland", "Venu Tammali" ], "comment": "28 pages, 5 figures", "categories": [ "math.NA" ], "abstract": "In many applications such as data compression, imaging or genomic data analysis, it is important to approximate a given tensor by a tensor that is sparsely representable. For matrices, i.e. 2-tensors, such a representation can be obtained via the singular value decomposition, which allows to compute best rank k-approximations. For very big matrices a low rank approximation using SVD is not computationally feasible. In this case different approximations are available. It seems that variants of CUR decomposition are most suitable. For d-mode tensors T with d>2, many generalizations of the singular value decomposition have been proposed to obtain low tensor rank decompositions. The most appropriate approximation seems to be best (r_1,...,r_d)-approximation, which maximizes the l_2 norm of the projection of T on a tensor product of subspaces U_1,...,U_d, where U_i is an r_i-dimensional subspace. One of the most common method is the alternating maximization method (AMM). It is obtained by maximizing on one subspace U_i, while keeping all other fixed, and alternating the procedure repeatedly for i=1,...,d. Usually, AMM will converge to a local best approximation. This approximation is a fixed point of a corresponding map on Grassmannians. We suggest a Newton method for finding the corresponding fixed point. We also discuss variants of CUR-approximation method for tensors. The first part of the paper is a survey on low rank approximation of tensors. The second new part of this paper is a new Newton method for best $(r_1,...,r_d)$-approximation. We compare numerically different approximation methods.", "revisions": [ { "version": "v1", "updated": "2014-10-22T16:02:54.000Z" } ], "analyses": { "subjects": [ "15A69", "58C30", "65C05", "65F30" ], "keywords": [ "low-rank approximation", "low rank approximation", "singular value decomposition", "low tensor rank decompositions", "newton method" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1410.6089F" } } }