Communication-avoiding parallel and sequential QR factorizations

We present parallel and sequential dense QR factorization algorithms that are optimized to avoid communication. Some of these are novel, and some extend earlier work. Communication includes both messages between processors (in the parallel case), and data movement between slow and fast memory (in either the sequential or parallel cases). Our first algorithm, Tall Skinny QR (TSQR), factors m

• Type: Journal
• Year: 2008
• Where: CORR
• Authors: James Demmel, Laura Grigori, Mark Hoemmen, Julien Langou
• Keywords: Algorithm, CORR 2008, Education, Fast Memory, Parallel Case