arXiv subjects

Andrew M. Bradley

Publications and source records attributed to Andrew M. Bradley.

2 recordsLinked to original sources

arXiv2012

Matrix-Free Approximate Equilibration

The condition number of a diagonally scaled matrix, for appropriately chosen scaling matrices, is often less than that of the original. Equilibration scales a matrix so that the scaled matrix's row and column norms are equal. Scaling can be approximate. We develop approximate equilibration algorithms for nonsymmetric and symmetric matrices having signed elements that access a matrix only by matrix-vector products.

math.NA↗

arXiv2011

H-Matrix and Block Error Tolerances

We describe a new method to map the requested error tolerance on an H-matrix approximation to the block error tolerances. Numerical experiments show that the method produces more efficient approximations than the standard method for kernels having singularity order greater than one, often by factors of 1.5 to 5 and at a lower computational cost.

math.NA↗