Software

 

I. Hnetynkova, M. Plesinger and Z. Strakos, MATLAB software for the paper ``The regularizing effect of the Golub-Kahan iterative bidiagonalization and revealing the noise level in the data'' (20.07.2009). We show how the information from the Golub-Kahan iterative bidiagonalization can be used for revealing the unknown level of the noise.You can download the files Shaw problem. The file shaw.m contains the standard routine constructing an aproximation of the Shaw problem (matrix, right-hand side, and the solution), see [P. C. Hansen, Regularization Tools, Version 4.0 for MATLAB 7.3, 2007].The file shaw_vpa.m contains a modified routine constructing an aproximation of the same problem as the prewious one, but using the high-precision arithmetic. Small testing problems with some experiments     software. Testing problem Image deblurring (Barbara)     software, results: images256, graphs256, images512, graphs512. Testing problem Image deblurring (Elephant)     software, results: images, graphs. Testing problem ODF (new MATLAB)     software, results: graphs. Testing problem ODF (old MATLAB)     software. The software will be continuously updated.

 

J. Duintjer Tebbens and G. Meurant, MATLAB software for the paper ``Any Ritz value behavior is possible for Arnoldi and for GMRES'' (22.05.2012). We give subroutines to construct examples with prescribed behavior of GMRES and Arnoldi. You can download the files here.