search for: katsikis

Displaying 2 results from an estimated 2 matches for "katsikis".

2012 Dec 12
3
R-2.15.2 changes in computation speed. Numerical precision?
Speaking of optimization and speeding up R calculations... I mentioned last week I want to speed up calculation of generalized inverses. On Debian Wheezy with R-2.15.2, I see a huge speedup using a souped up generalized inverse algorithm published by V. N. Katsikis, D. Pappas, Fast computing of theMoore-Penrose inverse matrix, Electronic Journal of Linear Algebra, 17(2008), 637-650. I was so delighted to see the computation time drop on my Debian system that I boasted to the WIndows users and gave them a test case. They answered back "there's no ben...
2012 Dec 05
1
Understanding svd usage and its necessity in generalized inverse calculation
...ood as, but faster than, svd. It appears to me work on this traces back to a speedup obtained by Courrieu, whose method takes about one-half as much time as the svd. P. Courrieu. Fast Computation of Moore-Penrose Inverse matrices. Neural Information Processing-Letters and Reviews, 8:25?29, 2005. Katsikis, Casilos N. and Dimitrios Pappas. 2008. Fast computing of the Moore-Penrose Inverse Matrix. Electronic Journal of Linear Algebra 17: 637-650. http://celc.cii.fc.ul.pt/iic/ela/ela-articles/articles/vol17_pp337-350.pdf Toutounian, F., & Ataei, A. (2009). A new method for computing Moore-Penrose...