Codes for almost block diagonal systems

Abstract We present a new set of codes for solving almost block diagonal systems of linear equations and for performing multiplicative operations with matrices represented using the same data structures. These data structures arise when solving ordinary differential equation boundary value problems with non-separated boundary conditions by finite differences, and when using spline collocation methods. Our codes are written in a modular form using the BLAS and are intended to take advantage of vector architecture and, to a limited extent, parallelism.