Some problem formulations are defined in block form and need to be implemented in terms of block operators. Examples include saddle point problems (ex5.cpp), DPG discretization (ex8.cpp), and problems ...

This package supports representing block-banded and banded-block-banded matrices by only storing the entries in the non-zero bands.

Abstract: In compressive sensing (CS), the restricted isometry property (RIP) is an important condition on measurement matrices which guarantees the recovery of sparse signals with undersampled ...

Department of Cyber-Physical Systems, Clark Atlanta University, Atlanta, GA, USA. where P is some reflection (symmetric signed permutation) matrix. Like U, the generalized reflexive matrices A arise ...

Abstract: The authors give a criterion of nonsingular block H- matrices and introduce the concepts of block $\alpha$ - bidiagonally dominant matrices. A new criterion for block H-matrices is given.

The natural questions are that whether the above results can be used to estimate the perturbation bounds for singular values of a block tridiagonal matrix, and how to get the eigenvalues perturbation ...

For the large sparse block two-by-two real nonsingular matrices, we establish a general framework of practical and efficient structured preconditioners through matrix transformation and matrix ...