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.