608 research outputs found
An Efficient Randomized Fixed-Precision Algorithm for Tensor Singular Value Decomposition
The existing randomized algorithms need an initial estimation of the tubal
rank to compute a tensor singular value decomposition. This paper proposes a
new randomized fixedprecision algorithm which for a given third-order tensor
and a prescribed approximation error bound, automatically finds an optimal
tubal rank and the corresponding low tubal rank approximation. The algorithm is
based on the random projection technique and equipped with the power iteration
method for achieving a better accuracy. We conduct simulations on synthetic and
real-world datasets to show the efficiency and performance of the proposed
algorithm
Cross Tensor Approximation Methods for Compression and Dimensionality Reduction
Cross Tensor Approximation (CTA) is a generalization of Cross/skeleton matrix and CUR Matrix Approximation (CMA) and is a suitable tool for fast low-rank tensor approximation. It facilitates interpreting the underlying data tensors and decomposing/compressing tensors so that their structures, such as nonnegativity, smoothness, or sparsity, can be potentially preserved. This paper reviews and extends stateof-the-art deterministic and randomized algorithms for CTA with intuitive graphical illustrations.We discuss several possible generalizations of the CMA to tensors, including CTAs: based on ber selection, slice-tube selection, and lateral-horizontal slice selection. The main focus is on the CTA algorithms using Tucker and tubal SVD (t-SVD) models while we provide references to other decompositions such as Tensor Train (TT), Hierarchical Tucker (HT), and Canonical Polyadic (CP) decompositions. We evaluate the performance of the CTA algorithms by extensive computer simulations to compress color and medical images and compare their performance.Fil: Ahmadi Asl, Salman. Skoltech - Skolkovo Institute Of Science And Technology; RusiaFil: Caiafa, César Federico. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Cichocki, Andrzej. Skolkovo Institute of Science and Technology; RusiaFil: Phan, Anh Huy. Skolkovo Institute of Science and Technology; RusiaFil: Tanaka, Toshihisa. Agricultural University Of Tokyo; JapónFil: Oseledets, Ivan. Skolkovo Institute of Science and Technology; RusiaFil: Wang, Jun. Skolkovo Institute of Science and Technology; Rusi
Matrix Factorization at Scale: a Comparison of Scientific Data Analytics in Spark and C+MPI Using Three Case Studies
We explore the trade-offs of performing linear algebra using Apache Spark,
compared to traditional C and MPI implementations on HPC platforms. Spark is
designed for data analytics on cluster computing platforms with access to local
disks and is optimized for data-parallel tasks. We examine three widely-used
and important matrix factorizations: NMF (for physical plausability), PCA (for
its ubiquity) and CX (for data interpretability). We apply these methods to
TB-sized problems in particle physics, climate modeling and bioimaging. The
data matrices are tall-and-skinny which enable the algorithms to map
conveniently into Spark's data-parallel model. We perform scaling experiments
on up to 1600 Cray XC40 nodes, describe the sources of slowdowns, and provide
tuning guidance to obtain high performance
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