Amesos2  Direct Sparse Solver Interfaces Version of the Day

Many thirdparty solvers support a vast amount of parameters to control factorization and solution. An effort has been made in Amesos2 to expose to users as many of those parameters as reasonably possible. Not all parameters may be supported, but if there is one that you would like to have exposed, then contact the Amesos2 developers and we may be able to work something out for you.
The following parameters are currently acted upon by Amesos2 solvers:
"Transpose"
: { true
 false
}. If true
, tells the solver to solve for We plan in the future to support the following parameters:
"Reindex"
: { true
 false
}. Put the matrix row and column indices into the range [0..n]. "AddZeroToDiag"
: { true
 false
}. "AddToDiag"
: string
. Where the given string is a representation of a scalar value to add to all diagonal entries of the matrix before factorization. Currently, the following SuperLU parameters/options are recognized and acted upon:
"Trans"
: { "NOTRANS"
 "TRANS"
 "CONJ"
}. Specifies whether to solve with the transpose system. "Equil"
: { true
 false
}. Specifies whether the solver to equilibrate the matrix before solving. "IterRefine"
: { "NO"
 "SLU_SINGLE"
 "SLU_DOUBLE"
 "EXTRA"
}. Specifies whether to perform iterative refinement, and in what precision to compute the residual. "SymmetricMode"
: { true
 false
}. "DiagPivotThresh"
: double
value. Specifies the threshold used for a diagonal to be considered an acceptable pivot. "ColPerm"
which takes one of the following: "NATURAL"
: natural ordering. "MMD_AT_PLUS_A"
: minimum degree ordering on the structure of . "MMD_ATA"
: minimum degree ordering on the structure of . "COLAMD"
: approximate minimum degree column ordering. (default) The following SuperLU_MT parameters/options are recognized:
"nprocs"
(int) : Specifies the number of threads to be spawned. Default is 1. "trans"
: { "NOTRANS"
 "TRANS"
 "CONJ"
}. Will also recognize the "Transpose"
: { true
 false
} option which is equivalent to "TRANS"
and "NOTRANS"
, respectively. "panel_size"
(int) : Specifies the number of consecutive columns to be treated as a unit of task. "relax"
(int) : Specifies the number of columns to be grouped as a relaxed supernode. "Equil"
: { true
 false
}. Specifies whether the solver to equilibrate the matrix before solving. "SymmetricMode"
: { true
 false
}. Specifies whether to use the symmetric mode. "DiagPivotThresh"
: double
value. Specifies the threshold used for a diagonal to be considered an acceptable pivot. "ColPerm"
which takes one of the following: "NATURAL"
: natural ordering. "MMD_AT_PLUS_A"
: minimum degree ordering on the structure of . "MMD_ATA"
: minimum degree ordering on the structure of . "COLAMD"
: approximate minimum degree column ordering. (default) Note that the nprocs
, panel_size
, and relax
options are recognized by SuperLU_MT but not by SuperLU. Note also that it is no typo in "trans", it really is lowercase (as opposed to uppercase in SuperLU)
Currently, the following SuperLU_DIST parameters/options are recognized:
"npcol"
(int) and "nprow"(int) : Specified together, these parameters set the size of the SuperLU_DIST processor grid to nprow
rows by npcol
columns. If these parameters are not set, the SuperLU_DIST interface uses a heuristic to pick the grid dimensions based on the number of processors in the matrix' communicator. "ColPerm"
which takes one of the following: "NATURAL"
: natural column ordering. "PARMETIS"
: use the ParMETIS TPL to order the columns. (default) "ReplaceTinyPivot"
: { true
 false
}. Specifies whether to replace tiny diagonals with during LU factorization. (default: true
) The Pardiso MKL parameters that are currently recognized are:
"IPARM(2)"
"IPARM(4)"
"IPARM(8)"
"IPARM(10)"
"IPARM(18)"
"IPARM(24)"
"IPARM(25)"
"IPARM(60)"
Please see the Pardiso MKL documentation for a summary of the meaning and valid values for each parameter.
The LAPACK interface supports the following parameters:
"Equilibrate"
(bool) : equilibrate the matrix before factorization. The default is true
.