@article{DDF2021,
-
author = {D’Ambra, Pasqua and Durastante, Fabio and Filippone, Salvatore},
-
title = {{{AMG Preconditioners for Linear Solvers towards Extreme Scale}},
-
journal = {arXiv e-preprints},
-
eprint = {2006.16147v3},
-
archivePrefix = {arXiv},
-
year={2021}
-
}
-
-
@Misc{psctoolkit-web-page,
-
author = {D’Ambra, Pasqua and Durastante, Fabio and Filippone, Salvatore},
-
title = {{PSCToolkit} {W}eb page},
-
url = {https://psctoolkit.github.io/},
-
howpublished = {\url{https://psctoolkit.github.io/}},
-
year = {2021}
-
}
-diff --git a/docs/html/userhtmlli5.html b/docs/html/userhtmlli5.html index 7203781c..b9362d17 100644 --- a/docs/html/userhtmlli5.html +++ b/docs/html/userhtmlli5.html @@ -3,8 +3,8 @@
string
der
’NONE’
Considered to use the PSBLAS Krylov solvers with no preconditioner.
’DIAG’L1-JACOBI’
Diagonal preconditioner. For any zero diagonal entry of the matrix to be preconditioned, the corresponding entry @@ -309,7 +309,7 @@ of the preconditioner is set to 1.
’GS’L1-GS’
Hybrid Gauss-Seidel (forward), that is, global block Jacobi with Gauss-Seidel as local solver.
’FBGS’L1-FBGS’
Symmetrized hybrid Gauss-Seidel, that is, forward Gauss-Seidel followed by backward Gauss-Seidel.
’BJAC’L1-BJAC’
Block-Jacobi with ILU(0) on the local blocks.
’AS’
Additive Schwarz (AS), with overlap 1 and ILU(0) on the local blocks.
’ML’
V-cycle with one hybrid forward Gauss-Seidel (GS) sweep as pre-smoother and one hybrid backward diff --git a/docs/html/userhtmlse5.html b/docs/html/userhtmlse5.html index b4a1075b..8f6ba4e7 100644 --- a/docs/html/userhtmlse5.html +++ b/docs/html/userhtmlse5.html @@ -3,8 +3,8 @@
smoother
class(amg_x_base_smoother_type)
The user-defined new smoother to be employed in the preconditioner.
solver
class(amg_x_base_solver_type)
The user-defined new solver to be employed in the preconditioner.
pass it as follows: -
+ ! sparse matrix and preconditioner + type(psb_dspmat_type) :: a + type(amg_dprec_type) :: prec + type(amg_d_tlu_solver_type) :: tlusv +...... + ! + ! prepare the preconditioner: an ML with defaults, but with TLU solver at + ! intermediate levels. All other parameters are at default values. + ! + call prec%init(’ML’, info) + call prec%hierarchy_build(a,desc_a,info) + nlv = prec%get_nlevs() + call prec%set(tlusv, info,ilev=1,ilmax=max(1,nlv-1)) + call prec%smoothers_build(a,desc_a,info) +
diff --git a/docs/html/userhtmlse7.html b/docs/html/userhtmlse7.html index be3f3a40..20a74c45 100644 --- a/docs/html/userhtmlse7.html +++ b/docs/html/userhtmlse7.html @@ -3,8 +3,8 @@
+ AMG4PSBLAS version 1.0 + Algebraic MultiGrid Preconditioners Package + based on PSBLAS (Parallel Sparse BLAS version 3.7) + (C) Copyright 2021 + Pasqua D’Ambra IAC-CNR, IT + Fabio Durastante University of Pisa and IAC-CNR, IT + Salvatore Filippone University of Rome Tor-Vergata and IAC-CNR, IT + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + 1. Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions, and the following disclaimer in the + documentation and/or other materials provided with the distribution. + 3. The name of the MLD2P4 group or the names of its contributors may + not be used to endorse or promote products derived from this + software without specific written permission. + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + ‘‘AS IS’’ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE MLD2P4 GROUP OR ITS CONTRIBUTORS + BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. +
@@ -83,44 +78,37 @@ class="cmr-12">abide by its terms: -
+ MLD2P4 version 2.2 + MultiLevel Domain Decomposition Parallel Preconditioners Package + based on PSBLAS (Parallel Sparse BLAS version 3.5) + (C) Copyright 2008-2018 + Salvatore Filippone + Pasqua D’Ambra + Daniela di Serafino + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + 1. Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions, and the following disclaimer in the + documentation and/or other materials provided with the distribution. + 3. The name of the MLD2P4 group or the names of its contributors may + not be used to endorse or promote products derived from this + software without specific written permission. + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + ‘‘AS IS’’ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE MLD2P4 GROUP OR ITS CONTRIBUTORS + BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. +
AMG4PSBLAS is distributed together with (a small part) of the graph-matching @@ -133,54 +121,52 @@ class="cmr-12">[9]. Per the license requirements, we reproduce the relative part -here. +class="cmr-12">. The relevant license is reproduced here: -
+// *********************************************************************** +// +// MatchboxP: A C++ library for approximate weighted matching +// Mahantesh Halappanavar (hala@pnnl.gov) +// Pacific Northwest National Laboratory +// // *********************************************************************** -
// -
// MatchboxP: A C++ library for approximate weighted matching -
// Mahantesh Halappanavar (hala@pnnl.gov) -
// Pacific Northwest National Laboratory -
// -
// *********************************************************************** -
// -
// Copyright (2021) Battelle Memorial Institute -
// All rights reserved. -
// -
// Redistribution and use in source and binary forms, with or without -
// modification, are permitted provided that the following conditions -
// are met: -
// -
// 1. Redistributions of source code must retain the above copyright -
// notice, this list of conditions and the following disclaimer. -
// -
// 2. Redistributions in binary form must reproduce the above copyright -
// notice, this list of conditions and the following disclaimer in the -
// documentation and/or other materials provided with the distribution. -
// -
// 3. Neither the name of the copyright holder nor the names of its -
// contributors may be used to endorse or promote products derived from -
// this software without specific prior written permission. -
// -
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS -
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE -
// COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, -
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, -
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; -
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER -
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN -
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -
// POSSIBILITY OF SUCH DAMAGE. -
// -
// ************************************************************************ -
diff --git a/docs/html/userhtmlse9.html b/docs/html/userhtmlse9.html index 220606fb..5a1864d1 100644 --- a/docs/html/userhtmlse9.html +++ b/docs/html/userhtmlse9.html @@ -3,8 +3,8 @@
a
type(in).
The sparse matrix structure containing the local part of the matrix 20].
desc_a
type(in).
The communication descriptor of a20].
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
amold
class( optional.
The desired dynamic type for internal matrix components; this 20].
vmold
class( optional.
The desired dynamic type for internal vector components; this allows e.g. running on GPUs.
imold
class( optional.
The desired dynamic type for internal integer vector components; this allows e.g. running on GPUs.
a
type(in).
The sparse matrix structure containing the local part of the matrix 20].
desc_a
type(in).
The communication descriptor of a20].
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
amold
class( optional.
The desired dynamic type for internal matrix components; this 20].
vmold
class( optional.
The desired dynamic type for internal vector components; this allows e.g. running on GPUs.
imold
class( optional.
The desired dynamic type for internal integer vector components; this allows e.g. running on GPUs.
The method can be used to build multilevel preconditioners too. diff --git a/docs/html/userhtmlsu12.html b/docs/html/userhtmlsu12.html index a13c92a3..cae2bdd9 100644 --- a/docs/html/userhtmlsu12.html +++ b/docs/html/userhtmlsu12.html @@ -3,8 +3,8 @@
x
type(kind_parameter), dimension(:), intent(in)—.
The local part of the vector x, single/double precision version of AMG4PSBLAS under use.
y
type(kind_parameter), dimension(:), intent(out)—.
The local part of the vector y, single/double precision version of AMG4PSBLAS under use.
desc_a
type(in).
The communication descriptor associated to the matrix to be preconditioned.
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
trans
character((in).
If trans -1).
work
type(kind_parameter), dimension(:), optional, target—.
Workspace. Its size should be at least 4, single/double precision version of AMG4PSBLAS under use.
info
integer,out).
Error code. If no error, 0 is returned. See Section for details.
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
iout
integer, optional.
The id of the file where the preconditioner description will be printed; the default is the standard output.
root
integer, optional.
The id of the process where the preconditioner description will be printed; the default is psb_root_.
verbosity
integer, optional.
The verbosity level of the description. Default value is 0. For a distributed multilevel preconditioner the size of the coarsematrices on every process.
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
amold
class( optional.
The desired dynamic type for internal matrix components; this 20].
pout
type(out).
The copy of the preconditioner data structure. Note that x , single/double precision version of AMG4PSBLAS under use.
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
global
logical, optional.
Whether the global or local preconditioner memory occupation is false..
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
vmold
class( optional.
The desired dynamic type for internal vector components; this allows e.g. running on GPUs.
info
integer,out).
Error code. If no error, 0 is returned. See Section 7 for details.
./configure --with-psblas=PSB-INSTALL-DIR -
which assumes that the various MPI compilers and support libraries are available in
‘--prefix=$HOME$HOME’.
might be configured with:
-
./configure --with-psblas=/opt/psblas-3.7/ \ -
--with-umfpackincdir=/usr/include/suitesparse/ -
Once the configure script has completed execution, it will have generated the file
To build the library the user will now enter
- followed (optionally) by
-
diff --git a/docs/html/userhtmlsu4.html b/docs/html/userhtmlsu4.html
index 6c25a03f..92856733 100644
--- a/docs/html/userhtmlsu4.html
+++ b/docs/html/userhtmlsu4.html
@@ -3,8 +3,8 @@
@@ -289,19 +288,19 @@ class="cmr-12">.
-
-
- contxt type(in). The communication context. ptype character(in) . The type of preconditioner. Its values are specified in Table 1. Note that strings are case insensitive. info integer,out). Error code. If no error, 0 is returned. See Section 7 for details. what character(len=*). The parameter to be set. It can be specified through its name; the
8. val integer or in). The value of the parameter to be set. The list of allowed values and
len=*), it is also treated as case insensitive. info integer,out). Error code. If no error, 0 is returned. See Section 7 for details. ilev integer,in). For the multilevel preconditioner, the level at which the
8). ilmax integer,in). For the multilevel preconditioner, when both ilev The levels are numbered in increasing order starting from the fin
one, i.e., level 1 is the finest level. pos character(in). Whether the other arguments apply only to the pre-smoother
not concern the smoothers,
class="cmtt-12">pos is ignored. idx integer,in). An auxiliary input argument that can be passed to the underlying
what val dfault cnts ’ML_CYCLE ’VCYCLE’
’ADD’ ’VCYCLE’ Multilevel cycle: V-cycle, W-cycle, K-cycle,
and additive composition. ’CYCLE_SWEEPS’ integer Any integer
number ≥ 1 1 1 Number of multilevel cycles. what val dfault cnts ’MIN_COARSE_SIZE_PER_PROCESS’ integer Any number
> 0 200 200 Coarse size threshold per process. The
aggregation stops if the global number of
variables of the computed coarsest matrix
@@ -730,17 +730,17 @@ multiplied by the number of processes
(see Note). ’MIN_COARSE_SIZE’ integer Any number
> 0 -1 -1 Coarse size threshold. The aggregation
stops if the global number of variables
of the computed coarsest matrix is lower
@@ -753,17 +753,17 @@ class="cmtt-10x-x-109">MIN_COARSE_SIZE_PER_PROCESS’. ’MIN_CR_RATIO’ real Any number
> 1 1.5 1.5 Minimum coarsening
ratio. The aggregation stops if the ratio
between the global matrix dimensions at
@@ -771,23 +771,23 @@ two consecutive levels is lower than or
equal to this threshold (see Note). ’MAX_LEVS’ integer Any integer
number > 1 20 20 Maximum number of levels. The
aggregation stops if the number of levels
reaches this value (see Note). ’PAR_AGGR_ALG ’DEC’,
’SYMDEC’,
’COUPLED’ ’DEC’ Parallel aggregation algorithm.
the SYMDEC option applies decoupled
@@ -815,7 +815,7 @@ class="cmmi-10x-x-109">AT . ’AGGR_TYPE ’SOC1’,
’MATCHBOXP’ ’SOC1’ Type of aggregation algorithm: currently,
for the
decoupled aggregation we implement two
@@ -856,13 +856,13 @@ package [9]. ’AGGR_SIZE’ integer Any integer
power of 2,
with
@@ -870,8 +870,8 @@ with
class="cmtt-10x-x-109">aggr_size ≥
-2 4 4 Maximum size of aggregates when the
coupled aggregation based on matching
is applied. For aggressive coarsening
@@ -883,7 +883,7 @@ and ’MATCHBOXP’ ’AGGR_PROL ’SMOOTHED’,
’UNSMOOTHED’ ’SMOOTHED’ Prolongator used by the aggregation
algorithm: smoothed or unsmoothed (i.e.,
tentative prolongator). what val dfault cnts ’AGGR_ORD ’NATURAL’
’DEGREE’ ’NATURAL’ Initial ordering of indices for
the decoupled aggregation algorithm:
either natural ordering or sorted by
@@ -1016,7 +1016,7 @@ descending degrees of the nodes in the
matrix graph. ’AGGR_THRESH Any real
number ∈
[0,1] 0.01 0.01 The threshold θ in the strength of
connection algorithm. See also the note
at the bottom of this table. ’AGGR_FILTER ’FILTER’
’NOFILTER’ ’NOFILTER’ Matrix used in computing the smoothed
prolongator: filtered or unfiltered. what val dfault cnts ’COARSE_MAT ’DIST’
’REPL’ ’REPL’ Coarsest matrix layout: distributed among the
processes or replicated on each of them. ’COARSE_SOLVE ’MUMPS’L1-FBGS’ See Note. See Note. Solver used at the coarsest level: sequential
LU from MUMPS, UMFPACK, or SuperLU
(plus triangular solve); distributed LU from
@@ -1255,7 +1255,7 @@ UMFPACK and SuperLU_Dist are available only in
double precision. ’COARSE_SUBSOLVE ’ILU’
’AINV’ See Note. See Note. Solver for the diagonal blocks of the coarsest
matrix, in case the block Jacobi solver is chosen
as coarsest-level solver: ILU(
what val dfault cts ’COARSE_SWEEPS’ integer Any
integer
number >
-0 10 10 Number of sweeps when JACOBI, GS or BJAC is
chosen as coarsest-level solver. ’COARSE_FILLIN’ integer Any
integer
number ≥
-0 0 0 Fill-in level p of the ILU factorizations and first
fill-in for the approximate inverses. ’COARSE_ILUTHRS Any real
number ≥
-0 0 0 Drop tolerance t in the ILU(p,t) factorization and
first drop-tolerance for the approximate inverses. what val dfault cnts ’BJAC_STOP ’FALSE’
’TRUE’ ’FALSE’ Select whether to use a stopping criterion for
the Block-Jacobi method used as a coarse
solver. ’BJAC_TRACE ’FALSE’
’TRUE’ ’FALSE’ Select whether to print a trace for the
calculated residual for the Block-Jacobi
method used as a coarse solver. ’BJAC_ITRACE’ integer Any integer
> 0 -1 -1 Number of iterations after which a trace is to
be printed. ’BJAC_RESCHECK’ integer Any integer
> 0 -1 -1 Number of iterations after which a residual is
to be calculated. ’BJAC_STOPTOL Any real
< 1 0 0 Tolerance for the stopping criterion on the
residual. ’KRM_METHOD ’CG’
’RGMRES’ ’FCG’ A string that defines the iterative method to
be used when employing a Krylov method
20] for further
information. ’KRM_KPREC Table 1 ’BJAC’ The one-level
preconditioners from the Table 1 can be used
for the coarse Krylov solver. ’KRM_SUB_SOLVE Table 5 ’ILU’ Solver for the diagonal blocks of the coarsest
matrix preconditioner, in case the block Jacobi
solver is chosen
@@ -1771,7 +1771,7 @@ The same caveat from Table 5 applies here. ’KRM_GLOBAL ’TRUE’,
’FALSE’ ’FALSE’ Choose between a global Krylov solver, all
unknowns on a single node, or a distributed
one. The default choice is the distributed
solver. ’KRM_EPS Real < 1 10-6 The stopping tolerance. ’KRM_IRST’ integer Integer
≥ 1 30 30 An integer specifying the restart parameter.
This is employed for the BiCGSTABL or RGMRES
methods, otherwise it is ignored. ’KRM_ISTOPC’ integer Integers
-1,2,3 2 2 If 1 then the method uses the normwise
backward error in the infinity norm; if 20] guide
for the details. ’KRM_ITMAX’ integer Integer
≥ 1 40 40 The maximum number of iterations to
perform. ’KRM_ITRACE’ integer Integer
≥ 0 -1 -1 If > 0 print out
an informational message about convergence
@@ -1893,23 +1893,23 @@ class="cmtt-10x-x-109">’ iterations. If = 0 print a
message in case of convergence failure. ’KRM_FILLIN’ integer Integer
≥ 0 0 0 Fill-in level p of the ILU factorizations and
first fill-in for the approximate inverses. what val dfault cnts ’SMOOTHER_TYPE ’JACOBI’L1-FBGS’ ’FBGS’ Type of smoother used in the multilevel
-point-Jacobi and Additive Schwarz.
class="cmr-10">It is ignored by one-level preconditioners. ’SUB_SOLVE ’JACOBI’
’AINV’ GS and and Additive Schwarz
one-level
preconditioners The local solver to be used with the
. See
class="cmr-10">Note for details on hybrid Gauss-Seidel. ’SMOOTHER_SWEEPS’ integer Any integer
number ≥ 0 1 Number of sweeps of the smoother or
,
class="cmr-10">respectively. ’SUB_OVR’ integer Any integer
number ≥ 0 1 Number of overlap layers, for Additive
Schwarz only. what val dfault cnts ’SUB_RESTR ’HALO’
’NONE’ ’HALO’ Type of restriction operator, for Additive
classical Addditive Schwarz smoother and
class="cmr-10">its RAS variant. ’SUB_PROL ’SUM’
’NONE’ ’NONE’ Type of prolongation operator, for Additive
’ for its RAS variant. ’SUB_FILLIN’ integer Any integer
number ≥ 0 0 Fill-in level p of the incomplete LU
class="cmr-10">factorizations. ’SUB_ILUTHRS Any real
number ≥ 0 0 Drop tolerance t )
class="cmr-10">factorization. ’MUMPS_LOC_GLOB ’LOCAL_SOLVER’
’GLOBAL_SOLVER’ ’GLOBAL_SOLVER’ Whether MUMPS should be used as a
only on the part of the matrix local to each
class="cmr-10">process. ’MUMPS_IPAR_ENTRY’ integer Any integer
number 0 Set an entry in the MUMPS integer control
optional
class="cmr-10">argument. ’MUMPS_RPAR_ENTRY’ real Any real number 0 Set an entry in the MUMPS real control
optional
class="cmr-10">argument. a type(in). The sparse matrix structure containing the local part of the matrix
20]. desc_a type(in). The communication descriptor of a20]. info integer,out). Error code. If no error, 0 is returned. See Section 7 for details.
make
-
make install
-
use psb_base_mod
-
use amg_prec_mod
-
use psb_krylov_mod
-
... ...
-
!
-
! sparse matrix
-
type(psb_dspmat_type) :: A
-
! sparse matrix descriptor
-
type(psb_desc_type) :: desc_A
-
! preconditioner
-
type(amg_dprec_type) :: P
-
! right-hand side and solution vectors
-
type(psb_d_vect_type) :: b, x
-
... ...
-
!
-
! initialize the parallel environment
-
call psb_init(ctxt)
-
call psb_info(ctxt,iam,np)
-
... ...
-
!
-
! read and assemble the spd matrix A and the right-hand side b
-
! using PSBLAS routines for sparse matrix / vector management
-
... ...
-
!
-
! initialize the default multilevel preconditioner, i.e. V-cycle
-
! with basic smoothed aggregation, 1 hybrid forward/backward
-
! GS sweep as pre/post-smoother and UMFPACK as coarsest-level
-
! solver
-
call P%init(’ML’,info)
-
!
-
! build the preconditioner
-
call P%hierarchy_build(A,desc_A,info)
-
call P%smoothers_build(A,desc_A,info)
-
-
!
-
! set the solver parameters and the initial guess
-
... ...
-
!
-
! solve Ax=b with preconditioned CG
-
call psb_krylov(’CG’,A,P,b,x,tol,desc_A,info)
-
... ...
-
!
-
! deallocate the preconditioner
-
call P%free(info)
-
!
-
! deallocate other data structures
-
... ...
-
!
-
! exit the parallel environment
-
call psb_exit(ctxt)
-
stop
-
... ...
-
! build a V-cycle preconditioner with 1 block-Jacobi sweep (with
-
! ILU(0) on the blocks) as pre- and post-smoother, and 8 block-Jacobi
-
! sweeps (with ILU(0) on the blocks) as coarsest-level solver
-
call P%init(’ML’,info)
-
call P%set(’SMOOTHER_TYPE’,’BJAC’,info)
-
call P%set(’COARSE_SOLVE’,’BJAC’,info)
-
call P%set(’COARSE_SWEEPS’,8,info)
-
call P%hierarchy_build(A,desc_A,info)
-
call P%smoothers_build(A,desc_A,info)
-
... ...
-
... ...
-
! build a W-cycle preconditioner with 2 hybrid Gauss-Seidel sweeps
-
! as pre- and post-smoother, a distributed coarsest
-
! matrix, and MUMPS as coarsest-level solver
-
call P%init(’ML’,info)
-
call P%set(’PAR_AGGR_ALG’,’COUPLED’,info)
-
call P%set(’AGGR_TYPE’,’MATCHBOXP’,info)
-
call P%set(’AGGR_SIZE’,8,info)
-
call P%set(’ML_CYCLE’,’WCYCLE’,info)
-
call P%set(’SMOOTHER_TYPE’,’FBGS’,info)
-
call P%set(’SMOOTHER_SWEEPS’,2,info)
-
call P%set(’COARSE_SOLVE’,’KRM’,info)
-
call P%hierarchy_build(A,desc_A,info)
-
call P%smoothers_build(A,desc_A,info)
-
... ...
-
... ...
-
! set RAS with overlap 2 and ILU(0) on the local blocks
-
call P%init(’AS’,info)
-
call P%set(’SUB_OVR’,2,info)
-
call P%bld(A,desc_A,info)
-
... ...
-
! solve Ax=b with preconditioned BiCGSTAB
-
call psb_krylov(’BICGSTAB’,A,P,b,x,tol,desc_A,info)
-
contxt ptype info what info ilev ilmax pos idx a type e val t character=*) ’ ’ integer ≥ 1
a type e val t integer > 0 integer > 0 real > 1 integer > 1 character=*) ’COUPLED’ ’DEC’ character=*) ’ ’ integer character=*) ’ ’ a type e val t character=*) ’DEGREE’ ’NATURAL’ real) ,1] character=*) ’NOFILTER’ ’NOFILTER’
a type e val t character=*) ’ ’ character=*) ’ character=*) ’ a type e val t integer integer real) a type e val t character=*) ’ ’ character=*) ’ ’ integer > 0 integer > 0 real) < 1 character=*) ’ ’ character=*) 1 ’ character=*) 5 ’ character=*) ’ ’ real) < 1 6 integer ≥ 1 integer integer ≥ 1 integer ≥ 0 integer ≥ 0 a type e val t character=*) ’ ’ character=*) ’ preconditioners integer 0 1 integer 0 1
a type e val t character=*) ’ ’ character=*) ’ ’ integer 0 0 real) 0 0 character=*) ’ ’ integer number 0 real Any real number 0
a desc_a info