Chapter 1 parallel sparse solver - freeFEM.org

2 CHAPTER 1. PARALLEL SPARSE SOLVER
To use parallel solver in FreeFem++, we need to load the dynamic library corresponding to this
solver. For example to use MUMPS solver as parallel solver in FreeFem, write in the .edp file load
”MUMPS FreeFem”.
When we not load libraries, the default sparse solver change (default sparse solver is umfpack).
The table 1.1 gives this new value for the different libraries.
default sparse solver
Libraries real complex
MUMPS FreeFem mumps mumps
real SuperLU DIST FreeFem SuperLU DIST previous solver
complex SuperLU DIST FreeFem previous solver SuperLU DIST
real pastix FreeFem pastix previous solver
complex pastix FreeFem previous solver pastix
hips FreeFem hips previous solver
hypre FreeFem hypre previous solver
parms FreeFem parms previous solver
Table 1.1: Default sparse solver for real and complex arithmetics when we load a parallel sparse
solver library
We also add functions (see Table 1.2) with no parameter to change the default sparse solver in the
.edp file. To used these functions, we need to load the library corresponding to the solver. An example
of using different parallel sparse solver for the same problem is given in testdirectsolvers.edp
(directory example+ + −mpi).
default sparse solver
function real complex
defaulttoMUMPS() mumps mumps
realdefaulttoSuperLUdist() SuperLU DIST previous solver
complexdefaulttoSuperLUdist() previous solver SuperLU DIST
realdefaultopastix() pastix previous solver
complexdefaulttopastix() previous solver pastix
defaulttohips() hips previous solver
defaulttohypre() hypre previous solver
defaulttoparms() parms previous solver
Table 1.2: Functions that allow to change default sparse solver for real and complex arithmetics
and the result of these functions
Example 1.1 (testdirectsolvers.edp)
load "../src/solver/MUMPS_FreeFem"
// default solver : real-> MUMPS, complex -> MUMPS
load "../src/solver/real_SuperLU_DIST_FreeFem"
// default solver : real-> SuperLU DIST, complex -> MUMPS
load "../src/solver/real_pastix_FreeFem"
// default solver : real-> pastix, complex -> MUMPS
// solving with pastix