Parallel Algorithms for Large Scale Macroeconometric Models
Bogdan OANCEA
Monica NEDELCU
Keywords
parallel algorithms,
linear algebra,
macroeconometric models
Abstract
Macroeconometric models with forward-looking variables
give raise to very large systems of equations that requires heavy computations.
These models was influenced by the development of new and efficient
computational techniques and they are an interesting testing ground
for the numerical methods addressed in this research. The most difficult
problem in solving such models is to obtain the solution of the linear
system that arises during the Newton step. For this purpose we have
used both direct methods based on matrix factorization and nonstationary
iterative methods, also called Krylov methods that provide an interesting
alternative to the direct methods. In this paper we present performance
results of both serial and parallel versions of the algorithms involved
in solving these models. Although parallel implementation of the most
dense linear algebra operations is a well understood process, the availability
of general purpose, high performance parallel dense linear algebra libraries
is limited by the complexity of implementation. This paper describes
PLSS – (Parallel Linear System Solver) - a library which provides routines
for linear system solving with an interface easy to use, that mirrors
the natural description of sequential linear algebra algorithms.