| Revista: | Computational & applied mathematics |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000310700 |
| ISSN: | 0101-8205 |
| Autors: | Santos, Reginaldo J1 Pierro, Alvaro R. de2 |
| Institucions: | 1Universidade Federal de Minas Gerais, Departamento de Matematica, Belo Horizonte, Minas Gerais. Brasil 2Universidade Estadual de Campinas, Departamento de Matematica Aplicada, Campinas, Sao Paulo. Brasil |
| Any: | 2006 |
| Volum: | 25 |
| Número: | 1 |
| Paginació: | 111-128 |
| País: | Brasil |
| Idioma: | Inglés |
| Tipo de documento: | Artículo |
| Enfoque: | Experimental, analítico |
| Resumen en inglés | We study the effect of the nonlinear dependence of the iterate x k of Conjugate Gradients method (CG) from the data b in the GCV procedure to stop the iterations. We compare two versions of using GCV to stop CG. In one version we compute the GCV function with the iterate x k depending linearly from the data b and the other one depending nonlinearly. We have tested the two versions in a large scale problem: positron emission tomography (PET). Our results suggest the necessity of considering the nonlinearity for the GCV function to obtain a reasonable stopping criterion |
| Disciplines | Matemáticas |
| Paraules clau: | Matemáticas puras, Validación cruzada, Tomografía, Gradiente conjugado |
| Keyword: | Mathematics, Pure mathematics, Cross validation, Tomography, Conjugate gradient |
| Text complet: | Texto completo (Ver HTML) |
