From aba9b297170d09c2f9d98aeb68e8eeb877c65c84 Mon Sep 17 00:00:00 2001 From: Salvatore Filippone Date: Thu, 15 Jul 2021 11:59:34 +0200 Subject: [PATCH] Fix samples/simple internal and external docs. --- docs/amg4psblas_1.0-guide.pdf | Bin 1830849 -> 1831453 bytes docs/html/userhtmlsu10.html | 38 +- docs/html/userhtmlsu11.html | 62 +- docs/html/userhtmlsu12.html | 64 +- docs/html/userhtmlsu13.html | 62 +- docs/html/userhtmlsu14.html | 22 +- docs/html/userhtmlsu15.html | 46 +- docs/html/userhtmlsu16.html | 114 ++-- docs/html/userhtmlsu6.html | 32 +- docs/html/userhtmlsu7.html | 34 +- docs/html/userhtmlsu9.html | 720 +++++++++++----------- docs/src/gettingstarted.tex | 32 +- docs/src/userinterface.tex | 17 +- samples/simple/pdegen/amg_dexample_ml.f90 | 19 +- samples/simple/pdegen/amg_sexample_ml.f90 | 19 +- 15 files changed, 650 insertions(+), 631 deletions(-) diff --git a/docs/amg4psblas_1.0-guide.pdf b/docs/amg4psblas_1.0-guide.pdf index 84b4b37aac69e604d7c250b83fecc958ea3ce221..4362844f29fce36f5d3ece4916f81039dd1c8936 100644 GIT binary patch delta 2152 zcmah|Yitx%6z0ypXuH@_=FZOSK)Y3eT}r1jvokw8fGCs}TOJh(q=}fglr7!3uxodz zXkv=VAcZJVG#rhOpuY?%4+EJ1iK0EjkLmk3aj3d> zeXvw*2TNn>FMASl9G)5Cr`v1Jum>u=UBxv;NY(NRRBh%%@JltWv^QO3-}0aqXuQn6 z?`dh84Rs!j;QB~C?Yb*0=ku7lN(%|Fl@Uz)xj)zw$ZyJ$u4(Ytb#}WiA(^HQ zH8d9DxYAVrOxBD&jq^Y4syK<@CLb_0lDba>(x-Xq|!-ZV7FWp;klT-P8_SXJl?pDbC z6!Ph=%u-oayIj937jVlpKz=a9!RfD9f4^x+2}5L3E0Z&3# z{{0w&J=|~*_HE$i!qp=84b=2;74$b?Az$Ps!`kaOxIWg$krg6~CrcnJY{&Y<-K~=i zMOPF(E+^|{b)qa!jFmUe%PpTpL`I^srl_*2$bYBUWe3EsBTZ`DG+NZ8qN`1YChMl$ z++>nh+|;bhlxNLoYMCCH_J1k%gfn8jpLtccJAM*3q9xH0%m}2Mo?Pm_jFoMF_WUgZQ9W$E-L8O9sU$qaS~SX20vD;76fd z6XC5vQD+W50mlc$#~X)ahvq3QQmCO2M)>MthZsxUyD8KnF0dHZ42ffz`f;#jNSwgT ze*iulB4_n{3ulJJ5cBLc_?`OuGB9pf42h-vPL0`g`y2}G6xvYe?rYFa5}1xM=ou!3 zte@e9VX;2=(n)8-G9*ko3jfwKUP@1*&_E%E`0hNsOcJ;(?<6QRY*5e;zu_<(Dv4wJU&%V$ zR1zK_3K(Gqh3Saj+UXGYQ@4piGliLm-+9v^$jveWQO^ji6j~5};6aCYkh!3fT2(0z`Ks`M%JpA%)q`vvSeC)UjiK1Fi}9AKywpg`v| zP=UmCX@{W08mOgEiG)thiH)W%xo>8G4q_mJgudfYdtPi^xS`oe(2%e%;aEBnPSiM7 z0tvsiIhKLKq1PNMiNb|v9Lq%Er$2D4DJXoDzF=lxDiV|1VBdN2Tt2x7$Ipv);G?A@ Ykof&+*m6OPR2aIhmX9Cb+}=|DC$jWQS^xk5 delta 1989 zcmai!Yitx%6vumKyIWYh_QBrWot?&R(ZZ~y)0v&;7DfA@P1W*{heji0OQ&|V-G$vn z+o%y`kWz`3D4fJ75+8{P5kbLGd034`6UC?>_y93Ll&Ez3(4=2f)O%-4jmE?e_m}hd z-*eBocV}PtF8jgx>^2KojODRPEwAOX%B*?Te9LcLWtCe2>uRgQs#p1r4(vHL1at1CeF+(8b_*1-# zw*Yt1#9Q$0tDz9pRYDVoV>ai*_amRA3!;>OC(G~=uPi8<3@!8Uus3N4N)q0EDzg3R zq$a3FGN$MWK~W@o)qHGv_C<00pA9wqeXe~XfJaN=@ZLx*Y^%UY*k6sG|2sX`)(Pke z;q|WWR0!|#8ImB&26Ttj|!97#6X5w1t}u}|?g*sF@XEWqmR!Md=f2njhROOlXCNU^np zvAg;1RAv~)?}&s`o3g1~-pm&o2h0b|fp}v=G5CCT-~lt2r;g5VN@X(Hf}7|u-PqQ= z+3Q9gOc(mySWniq3_cf^4Bp&4klvIkn7#1W_hAfop2vYlQyIETllk6szK~1zY$a(o zFxSOkiX?{I;6Q3PyS0#CN<2Nm7y3<7Sm({YxWs2&a|spdeBLY+(wTeRT|`F><*zB+ zV5+ZR=I}oRGVj)R`-@&6{SBsusf5hjpUT|pl+o$AZqStr@kUt}`8Dam^gt>%FdUb} zBv1R$Ww#H~o!g4>@2zebrxn+nEA3u5>qh^h3;X>GSQ+uCy871}bN7Xc<*??#&^Z|U z0|%gaD0CCd><(SEbH`AKtT0&-vRJaB_KqR$Xx9=|B0m9Hk(CB9u~-xr$Nf#++1_^Y zMlrs9)8~#sX zKmIM(;A5cCe&a`O6ydrOrUa?&6e}pY5UyDZD<-%)My-G?6I>0``4T)$ee*QDIl(no zW!KR?2TLh@D17KMxH7@1%*RK8;eo5 zj^a9s>nW~9p?Cm(E^>>Q+eC;?k`DS#!;O<%n6VDPdg6D#6L2ctOyw;UT@-C7ba|tb z=%ntg6e}riLE+c|C(+H6Fe3!$;2MfmD7@-*_-K+G_4sZmPI3+9d$u{k9>nsS;o2!q z%L<~zNV%SECIEwTJ zVTK60(YE1 zcj#qDK;DyK$@C0MZiHbwP~>D0#->S=Umb=+(_8~{xgX9=b0WiJATUF&)_)C%Gh9v6 z_W88H2%T-DmZAc&>)vx>Rn#TV%8bxyMq-F9JPZ%ba9xi+@uMS95Nn@xEETb5K6ES% zv9nW-rK2dm$*~L+-BRyZNfdo(y<;__=+`BVwG?sM3dg#E9 -

[nextMethod hierarchy_build

-

-

+

call p,info)

-

This method builds the hierarchy of matrices and restriction/prolongation operators for the multilevel preconditioner init and set. -

Arguments

a

type(psb_).

The sparse matrix structure containing the local part of the matrix to be preconditioned. Note that ].

desc_a

type(psb_desc_type).

The communication descriptor of a. See the PSBLAS User’s Guide @@ -136,9 +136,9 @@ class="cmr-12">].

info

integer, ).

Error code. If no error, 0 is returned. See Section 

-

[next] [up]

-

diff --git a/docs/html/userhtmlsu11.html b/docs/html/userhtmlsu11.html index 08501195..da684b86 100644 --- a/docs/html/userhtmlsu11.html +++ b/docs/html/userhtmlsu11.html @@ -10,7 +10,7 @@ -

[nextMethod smoothers_build

-

-

+

call p,imold])

-

This method builds the smoothers and the coarsest-level solvers for the multilevel preconditioner  5.3). -

Arguments

@@ -262,7 +262,7 @@ class="td11">

a

type(psb_).

The sparse matrix structure containing the local part of the matrix to be preconditioned. Note that ].

desc_a

type(psb_desc_type).

The communication descriptor of a. See the PSBLAS User’s Guide @@ -150,9 +150,9 @@ class="cmr-12">].

info

integer, ).

Error code. If no error, 0 is returned. See Section 7 for details.

amold

class(psb_optional.

The desired dynamic type for internal matrix components; this allows e.g. running on GPUs; it needs not be the same on all @@ -205,9 +205,9 @@ class="cmr-12">].

vmold

class(psb_optional.

The desired dynamic type for internal vector components; this allows e.g. running on GPUs.

imold

class(psb_i_base_vect_typeoptional.

The desired dynamic type for internal integer vector components; this allows e.g. running on GPUs.

-

[next] [up]

-

diff --git a/docs/html/userhtmlsu12.html b/docs/html/userhtmlsu12.html index 32e905c0..4f4c7dec 100644 --- a/docs/html/userhtmlsu12.html +++ b/docs/html/userhtmlsu12.html @@ -10,7 +10,7 @@ -

[next5.5 Method build

-

-

+

call p,imold])

-

This method builds the preconditioner p according to the requirements made by the @@ -83,7 +83,7 @@ class="cmtt-12">smoothers_build, whose nomenclature would however be somewhat unnatural when dealing with simple one-level preconditioners. -

Arguments

a

type(psb_).

The sparse matrix structure containing the local part of the matrix to be preconditioned. Note that ].

desc_a

type(psb_desc_type).

The communication descriptor of a. See the PSBLAS User’s Guide @@ -158,9 +158,9 @@ class="cmr-12">].

info

integer, ).

Error code. If no error, 0 is returned. See Section 7 for details.

amold

class(psb_optional.

The desired dynamic type for internal matrix components; this allows e.g. running on GPUs; it needs not be the same on all @@ -213,9 +213,9 @@ class="cmr-12">].

vmold

class(psb_optional.

The desired dynamic type for internal vector components; this allows e.g. running on GPUs.

imold

class(psb_i_base_vect_typeoptional.

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. @@ -272,7 +272,7 @@ class="cmr-12">The method can be used to build multilevel preconditioners too.

[next] [up]

-

diff --git a/docs/html/userhtmlsu13.html b/docs/html/userhtmlsu13.html index 6f194dd5..aec509c3 100644 --- a/docs/html/userhtmlsu13.html +++ b/docs/html/userhtmlsu13.html @@ -10,7 +10,7 @@ -

[next5.6 Method apply

-

-

+

call p,work])

-

This method computes y = psb_krylov and hence it is completely transparent to the user. -

Arguments

x

type(kind_parameter), dimension(:), intent(in)—.

The local part of the vector x. Note that , single/double class="cmr-12">precision version of AMG4PSBLAS under use.

y

type(kind_parameter), dimension(:), intent(out)—.

The local part of the vector y. Note that , single/double class="cmr-12">precision version of AMG4PSBLAS under use.

desc_a

type(psb_desc_type).

The communication descriptor associated to the matrix to be preconditioned.

info

integer, ).

Error code. If no error, 0 is returned. See Section 7 for details.

trans

character(lenin).

If trans = 1).

work

type(kind_parameter), dimension(:), optional, target—.

Workspace. Its size should be at least 4 

-

[next] [up]

-

diff --git a/docs/html/userhtmlsu14.html b/docs/html/userhtmlsu14.html index 9dab129c..d2f9804d 100644 --- a/docs/html/userhtmlsu14.html +++ b/docs/html/userhtmlsu14.html @@ -10,7 +10,7 @@ -

[next5.7 Method free

-

-

+

call p,info)

-

This method deallocates the preconditioner data structure p. -

Arguments

info

integer, ).

Error code. If no error, 0 is returned. See Section 

-

[next] [up]

-

diff --git a/docs/html/userhtmlsu15.html b/docs/html/userhtmlsu15.html index 8c3cfa76..07ff43a3 100644 --- a/docs/html/userhtmlsu15.html +++ b/docs/html/userhtmlsu15.html @@ -10,7 +10,7 @@ -

[next5.8 Method descr

-

-

+

call p verbosity])

-

This method prints a description of the preconditioner p to the standard output or to a @@ -68,7 +68,7 @@ class="cmtt-12">build, have been called. -

Arguments

info

integer, ).

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 values higher than 0, it prints out further information, e.g., for @@ -174,7 +174,7 @@ class="td11">

-

[next] [up]

-

diff --git a/docs/html/userhtmlsu16.html b/docs/html/userhtmlsu16.html index 6b6ab93f..122093bf 100644 --- a/docs/html/userhtmlsu16.html +++ b/docs/html/userhtmlsu16.html @@ -10,7 +10,7 @@ -

[prev]

class="cmr-12">5.9 Auxiliary Methods -

Various functionalities are implemented as additional methods of the preconditioner object. -

+

5.9.1 Method: dump
-

-

+

call p,global_num])

-

Dump on file. -

Arguments

info

integer, ).

Error code. If no error, 0 is returned. See Section 7 for details.

amold

class(psb_optional.

The desired dynamic type for internal matrix components; this allows e.g. running on GPUs; it needs not be the same on all @@ -134,15 +134,15 @@ class="cmr-12">.

-

+

5.9.2 Method: clone
-

-

+

call p)
-

Create a (deep) copy of the preconditioner object. -

Arguments

pout

type(amg_).

The copy of the preconditioner data structure. Note that x must @@ -199,9 +199,9 @@ class="cmr-12">, single/double precision class="cmr-12">version of AMG4PSBLAS under use.

info

integer, ).

Error code. If no error, 0 is returned. See Section for details.

-

+

5.9.3 Method: sizeof
-

-

+

sz =

global

logical, optional.

Whether the global or local preconditioner memory occupation is desired. Default: .

Return memory footprint in bytes. -

+

5.9.4 Method: allocate_wrk
-

-

+

call p vmold])

-

Allocate internal work vectors. Each application of the preconditioner uses a number of work vectors which are allocated internally as necessary; therefore allocation and @@ -326,7 +326,7 @@ class="cmr-12">argument to the apply method. -

Arguments

info

integer, ).

Error code. If no error, 0 is returned. See Section 7 for details.

vmold

class(psb_optional.

The desired dynamic type for internal vector components; this allows e.g. running on GPUs.

-

+

5.9.5 Method: free_wrk
-

-

+

call p(info)

-

Deallocate internal work vectors. -

Arguments

info

integer, ).

Error code. If no error, 0 is returned. See Section . ! 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) +  call P%init(ctxt,’ML’,info) ! ! build the preconditioner   call P%hierarchy_build(A,desc_A,info) @@ -169,8 +169,8 @@ class="cmr-12">. ! 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) +! solve Ax=b with preconditioned FCG +  call psb_krylov(’FCG’,A,P,b,x,tol,desc_A,info)   ... ... ! ! deallocate the preconditioner @@ -296,7 +296,7 @@ class="cmr-12">. ! 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%init(ctxt,’ML’,info)   call P%set(’SMOOTHER_TYPE’,’BJAC’,info)   call P%set(’COARSE_SOLVE’,’BJAC’,info)   call P%set(’COARSE_SWEEPS’,8,info) @@ -323,25 +323,27 @@ class="content">setup of a multilevel preconditioner based on the default decoup

-

+

 ... ...
 ! 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%init(ctxt,’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(’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%set(’COARSE_MAT’,’DIST’,info)
+  call P%set(’KRM_METHOD’,’FCG’,info)
   call P%hierarchy_build(A,desc_A,info)
   call P%smoothers_build(A,desc_A,info)
 ... ...
-

+


Listing 3: setup of a multilevel preconditioner based on the coupled coarsening using @@ -353,7 +355,7 @@ weighted matching
-

@@ -361,18 +363,18 @@ weighted matching
-

+

 ... ...
 ! set RAS with overlap 2 and ILU(0) on the local blocks
-  call P%init(’AS’,info)
+  call P%init(ctxt,’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)
-

+


Listing 4: setup of a one-level Schwarz preconditioner.
@@ -383,7 +385,7 @@ class="content">setup of a one-level Schwarz preconditioner.

[next] [up]

-

diff --git a/docs/html/userhtmlsu7.html b/docs/html/userhtmlsu7.html index f6633c56..57eae31c 100644 --- a/docs/html/userhtmlsu7.html +++ b/docs/html/userhtmlsu7.html @@ -10,7 +10,7 @@ -

[prev]

class="cmr-12">4.2 GPU example -

The code discussed here shows how to set up a program exploiting the combined GPU capabilities of PSBLAS and AMG4PSBLAS. The code example is available in the @@ -36,14 +36,14 @@ class="cmr-12">capabilities of PSBLAS and AMG4PSBLAS. The code example is availa class="cmr-12">source distribution directory amg4psblas/examples/gpu. -

First of all, we need to include the appropriate modules and declare some auxiliary variables: -

@@ -51,7 +51,7 @@ class="cmr-12">variables:
-

+

 program amg_dexample_gpu
   use psb_base_mod
@@ -69,7 +69,7 @@ program amg_dexample_gpu
   type(psb_i_vect_gpu)       :: igmold
  
-

+


Listing 5: setup of a GPU-enabled test program part one.
@@ -77,7 +77,7 @@ class="content">setup of a GPU-enabled test program part one.

In this particular example we are choosing to employ a HLG data structure for @@ -85,7 +85,7 @@ class="cmr-12">data structure for class="cmr-12">sparse matrices on GPUs; for more information please refer to the PSBLAS-EXT users’ guide. -

We then have to initialize the GPU environment, and pass the appropriate MOLD variables to the build methods (see also the PSBLAS and PSBLAS-EXT users’ @@ -94,7 +94,7 @@ class="cmr-12">guides). -

@@ -102,7 +102,7 @@ class="cmr-12">guides).
-

+

   call psb_init(ctxt)
   call psb_info(ctxt,iam,np)
@@ -116,7 +116,7 @@ class="cmr-12">guides).
   call prec%smoothers_build(a,desc_a,info, amold=agmold, vmold=vgmold, imold=igmold)
  
-

+


Listing 6: setup of a GPU-enabled test program part two.
@@ -124,7 +124,7 @@ class="content">setup of a GPU-enabled test program part two.

Finally, we convert the input matrix, the descriptor and the vectors to use a GPU-enabled internal storage format. We then preallocate the preconditioner @@ -135,7 +135,7 @@ class="cmr-12">GPU environment -

@@ -143,7 +143,7 @@ class="cmr-12">GPU environment
-

+

   call desc_a%cnv(mold=igmold)
   call a%cscnv(info,mold=agmold)
@@ -167,7 +167,7 @@ class="cmr-12">GPU environment
   stop
  
-

+


Listing 7: setup of a GPU-enabled test program part three.
@@ -175,7 +175,7 @@ class="content">setup of a GPU-enabled test program part three.

It is very important to employ solvers that are suited to the GPU, i.e. solvers that do NOT employ triangular system solve kernels. Solvers that satisfy this constraint @@ -193,7 +193,7 @@ class="cmtt-12">INVT

  • AINV
    • -

    and their ℓ1 ). class="newline" />

    Remark 3. Many of the coarsest-level solvers cannot be used with both replicated +class="cmr-12">Many of the coarsest-level solvers apply to a specific coarsest-matrix and distributed coarsest-matrix layouts; therefore, setting the solver after the layout +class="cmr-12">layout; therefore, setting the solver after the layout may change the layout to either may change the layout. Similarly, setting the layout after the solver may change the +class="cmr-12">distributed or replicated. Similarly, setting the layout after the solver may change the solver. -

    More precisely, UMFPACK and SuperLU require the coarsest-level matrix to be replicated, while SuperLUsingle Gauss-Seidel sweep, respectively, which are very poor solvers. -

    On the other hand, the distributed layout can be used with any solver but UMFPACK and SuperLU; therefore, if any of these two solvers has already been @@ -514,13 +514,13 @@ class="cmr-12">_Dist or KRM have been class="cmr-12">previously set, the coarsest-level solver is changed to the default sequential solver. -

    In a parallel setting with many cores, we suggest to the users to change the default coarsest solver for using the KRM choice, i.e. a parallel distributed iterative solution of the coarsest system based on Krylov methods. -

    Remark 4. The argument idx . -

    @@ -553,7 +553,7 @@ class="cmr-12">.
    -

    +

    +class="td11">

    1

    Parameters defining the aggregation algorithm.

    @@ -954,7 +954,7 @@ class="content">Parameters defining the aggregation algorithm.

    +

    what

    		type

    val

    deault

    cots

    ’ML_CYCLE’

    character(len=*)

    ’VCYCLE’ -

    ’WCYCLE’ -

    ’KCYCLE’ -

    ’ADD’

    ’VCYCLE’

    Multilevel cycle: V-cycle, W-cycle, K-cycle, +class="td11">

    Multilevel cycle: V-cycle, W-cycle, K-cycle, and additive composition.

    ’CYCLE_SWEEPS’

    integer

    Any integer -

    number

    Any integer +

    number ≥ 1

    1

    Number of multilevel cycles.

    Number of multilevel cycles.

    -

    @@ -669,7 +669,7 @@ applied.
    -

    +

    @@ -683,7 +683,7 @@ id="TBL-5-4">

    what

    		type

    val

    deault

    cots

    ’MIN_COARSE_SIZE_PER_PROCESS’

    integer

    Any number -

    Any number +

    > 0

    200

    Coarse size threshold per process. The +class="td11">

    200

    Coarse size threshold per process. The aggregation stops if the global number of variables of the computed coarsest matrix is lower than or equal to this threshold @@ -737,17 +737,17 @@ multiplied by the number of processes

    ’MIN_COARSE_SIZE’

    integer

    Any number -

    Any number +

    > 0

    -1

    Coarse size threshold. The aggregation +class="td11">

    -1

    Coarse size threshold. The aggregation stops if the global number of variables of the computed coarsest matrix is lower than or equal @@ -760,17 +760,17 @@ class="cmtt-10x-x-109">’.

    ’MIN_CR_RATIO’

    real

    Any number -

    Any number +

    > 1

    1.5

    Minimum coarsening +class="td11">

    1.5

    Minimum coarsening ratio. The aggregation stops if the ratio between the global matrix dimensions at two consecutive levels is lower than or @@ -778,41 +778,41 @@ equal to this threshold (see Note).

    ’MAX_LEVS’

    integer

    Any integer -

    number

    Any integer +

    number > 1

    20

    Maximum number of levels. The +class="td11">

    20

    Maximum number of levels. The aggregation stops if the number of levels reaches this value (see Note).

    ’PAR_AGGR_ALG’

    character(len=*)

    ’DEC’, ’SYMDEC’, ’COUPLED’

    ’DEC’

    Parallel aggregation algorithm. -

    the

    Parallel aggregation algorithm. +

    the SYMDEC option applies decoupled aggregation to the sparsity pattern of T .

    ’AGGR_TYPE’

    character(len=*)

    ’SOC1’, @@ -843,11 +843,11 @@ class="cmtt-10x-x-109">’, class="cmtt-10x-x-109">’MATCHBOXP’

    ’SOC1’

    Type of aggregation algorithm: currently, +class="td11">

    Type of aggregation algorithm: currently, for the decoupled aggregation we implement two measures of strength of connection, the @@ -863,22 +863,22 @@ href="userhtmlli5.html#XMatchBoxP">9].

    ’AGGR_SIZE’

    integer

    Any integer -

    power of 2, +class="td11">

    Any integer +

    power of 2, with aggr_size ≥ 2

    4

    Maximum size of aggregates when the +class="td11">

    4

    Maximum size of aggregates when the coupled aggregation based on matching is applied. For aggressive coarsening with size of aggregate larger than 8 @@ -890,16 +890,16 @@ class="cmtt-10x-x-109">’MATCHBOXP’

    ’AGGR_PROL’

    character(len=*)

    ’SMOOTHED’, @@ -907,11 +907,11 @@ class="cmtt-10x-x-109">’, class="cmtt-10x-x-109">’UNSMOOTHED’

    ’SMOOTHED’

    Prolongator used by the aggregation +class="td11">

    Prolongator used by the aggregation algorithm: smoothed or unsmoothed (i.e., tentative prolongator).

    Parameters defining the aggregation algorithm (continued).

    @@ -1097,7 +1097,7 @@ class="content">Parameters defining the aggregation algorithm (continued). -

    +

    @@ -1111,7 +1111,7 @@ id="TBL-7-4">

    @@ -1478,7 +1482,7 @@ class="content">Parameters defining the solver at the coarsest level (continued) -

    @@ -1486,7 +1490,7 @@ class="content">Parameters defining the solver at the coarsest level (continued)
    -

    +

    @@ -1500,7 +1504,7 @@ id="TBL-8-4">

    +class="td11">

    The stopping tolerance.

    Additional parameters defining the solver at the coarsest level. -

    @@ -1940,7 +1944,7 @@ class="content">Additional parameters defining the solver at the coarsest level.
    -

    +

    what

    		type

    val

    deault

    cots

    ’AGGR_ORD’

    character(len=*)

    ’NATURAL’ -

    ’DEGREE’

    ’NATURAL’

    Initial ordering of indices for +class="td11">

    Initial ordering of indices for the decoupled aggregation algorithm: either natural ordering or sorted by descending degrees of the nodes in the @@ -1023,44 +1023,44 @@ matrix graph.

    ’AGGR_THRESH’

    real(kind_parameter)

    Any real -

    number 

    Any real +

    number ∈ [0,1]

    0.01

    The threshold

    0.01

    The threshold θ in the strength of connection algorithm. See also the note at the bottom of this table.

    ’AGGR_FILTER’

    character(len=*)

    ’FILTER’ -

    ’NOFILTER’

    ’NOFILTER’

    Matrix used in computing the smoothed +class="td11">

    Matrix used in computing the smoothed prolongator: filtered or unfiltered.

    what

    		type

    val

    deault

    cots

    ’COARSE_MAT’

    character(len=*)

    ’DIST’ -

    ’REPL’

    ’REPL’

    Coarsest matrix layout: distributed among the +class="td11">

    Coarsest matrix layout: distributed among the processes or replicated on each of them.

    ’COARSE_SOLVE’

    character(len=*)

    ’MUMPS’ -

    ’UMF’ -

    ’SLU’ -

    ’SLUDIST’ -

    ’ILU’ +

    ’JACOBI’ -

    ’GS’ -

    ’BJAC’ -

    ’KRM’ -

    ’L1-JACOBI’ -

    ’L1-BJAC’ -

    ’L1-FBGS’

    See Note.

    Solver used at the coarsest level: sequential +class="td11">

    See Note.

    Solver used at the coarsest level: sequential LU from MUMPS, UMFPACK, or SuperLU (plus triangular solve); distributed LU from MUMPS or SuperLU_Dist (plus triangular solve); @@ -1262,53 +1266,53 @@ double precision.

    ’COARSE_SUBSOLVE’

    character(len=*)

    ’ILU’ -

    ’ILUT’ -

    ’MILU’ -

    ’MUMPS’ -

    ’SLU’ -

    ’UMF’ -

    ’INVT’ -

    ’INVK’ -

    ’AINV’

    See Note.

    Solver for the diagonal blocks of the coarsest +class="td11">

    See Note.

    Solver for the diagonal blocks of the coarsest matrix, in case the block Jacobi solver is chosen as coarsest-level solver: ILU(p), ILU(ILU otherwise.

    what

    		type

    val

    deault

    cos

    ’COARSE_SWEEPS’

    integer

    Any +class="td11">

    Any integer -

    number

    number > 0

    10

    Number of sweeps when

    10

    Number of sweeps when JACOBI, GS or BJAC is @@ -1413,39 +1417,39 @@ chosen as coarsest-level solver.

    ’COARSE_FILLIN’

    integer

    Any +class="td11">

    Any integer -

    number

    number ≥ 0

    0

    Fill-in level

    0

    Fill-in level p of the ILU factorizations and first fill-in for the approximate inverses.

    ’COARSE_ILUTHRS’

    real(kind_parameter)

    Any real -

    number

    Any real +

    number ≥ 0

    0

    Drop tolerance

    0

    Drop tolerance t in the ILU(p,t) factorization and first drop-tolerance for the approximate inverses.

    what

    		type

    val

    deault

    cots

    ’BJAC_STOP’

    character(len=*)

    ’FALSE’ -

    ’TRUE’

    ’FALSE’

    Select whether to use a stopping criterion for +class="td11">

    Select whether to use a stopping criterion for the Block-Jacobi method used as a coarse solver.

    ’BJAC_TRACE’

    character(len=*)

    ’FALSE’ -

    ’TRUE’

    ’FALSE’

    Select whether to print a trace for the +class="td11">

    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 -

    Any integer +

    > 0

    -1

    Number of iterations after which a trace is to +class="td11">

    -1

    Number of iterations after which a trace is to be printed.

    ’BJAC_RESCHECK’

    integer

    Any integer -

    Any integer +

    > 0

    -1

    Number of iterations after which a residual is +class="td11">

    -1

    Number of iterations after which a residual is to be calculated.

    ’BJAC_STOPTOL’

    real(kind_parameter)

    Any real -

    Any real +

    < 1

    0

    Tolerance for the stopping criterion on the +class="td11">

    0

    Tolerance for the stopping criterion on the residual.

    ’KRM_METHOD’

    character(len=*)

    ’CG’ -

    ’FCG’ -

    ’CGS’ -

    ’CGR’ -

    ’BICG’ -

    ’BICGSTAB’ -

    ’BICGSTABL’ -

    ’RGMRES’

    ’FCG’

    A string that defines the iterative method to +class="td11">

    A string that defines the iterative method to be used when employing a Krylov method ’

    ’KRM_KPREC’

    character(len=*)

    Table 

    Table 1

    ’BJAC’

    The one-level +class="td11">

    The one-level preconditioners from the Table 1 can be used for the coarse Krylov solver.

    ’KRM_SUB_SOLVE’

    character(len=*)

    Table 

    Table 5

    ’ILU’

    Solver for the diagonal blocks of the coarsest +class="td11">

    Solver for the diagonal blocks of the coarsest matrix preconditioner, in case the block Jacobi solver is chosen as 5 applies here.

    ’KRM_GLOBAL’

    character(len=*)

    ’TRUE’, @@ -1795,46 +1799,46 @@ class="cmtt-10x-x-109">’, class="cmtt-10x-x-109">’FALSE’

    ’FALSE’

    Choose between a global Krylov solver, all +class="td11">

    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(kind_parameter)

    Real

    Real < 1

    10

    10-6

    The stopping tolerance.

    ’KRM_IRST’

    integer

    Integer -

    Integer +

    ≥ 1

    30

    An integer specifying the restart parameter. +class="td11">

    30

    An integer specifying the restart parameter. This is employed for the BiCGSTABL or RGMRES @@ -1842,16 +1846,16 @@ methods, otherwise it is ignored.

    ’KRM_ISTOPC’

    integer

    Integers +class="td11">

    Integers 1,2,3

    2

    If

    2

    If 1 then the method uses the normwise backward error in the infinity norm; if 2, the @@ -1864,32 +1868,32 @@ for the details.

    ’KRM_ITMAX’

    integer

    Integer -

    Integer +

    ≥ 1

    40

    The maximum number of iterations to +class="td11">

    40

    The maximum number of iterations to perform.

    ’KRM_ITRACE’

    integer

    Integer -

    Integer +

    ≥ 0

    -1

    If

    -1

    If > 0 print out an informational message about convergence every

    ’KRM_FILLIN’

    integer

    Integer -

    Integer +

    ≥ 0

    0

    Fill-in level

    0

    Fill-in level p of the ILU factorizations and first fill-in for the approximate inverses.

    @@ -2274,7 +2278,7 @@ preconditioner. -

    @@ -2282,7 +2286,7 @@ preconditioner.
    -

    +

    what

    		type

    val

    deault

    cots

    ’SMOOTHER_TYPE’

    character(len=*)

    ’JACOBI’ -

    ’GS’ -

    ’BGS’ -

    ’BJAC’ -

    ’AS’ -

    ’L1-JACOBI’ -

    ’L1-BJAC’ -

    ’L1-FBGS’

    ’FBGS’

    Type of smoother used in the multilevel preconditioner: point-Jacobi, hybrid @@ -2056,21 +2060,21 @@ class="cmr-10">–hybrid (forward) Gauss-Seidel, class="cmmi-10">ℓ1-point-Jacobi and Additive Schwarz. -

    It is ignored by one-level preconditioners.

    ’SUB_SOLVE’

    character(len=*)

    ’JACOBI’ @@ -2078,47 +2082,47 @@ class="cmtt-10">’ class="cmtt-10">’GS’ -

    ’BGS’ -

    ’ILU’ -

    ’ILUT’ -

    ’MILU’ -

    ’MUMPS’ -

    ’SLU’ -

    ’UMF’ -

    ’INVT’ -

    ’INVK’ -

    ’AINV’

    GS and BGS multilevel class="cmr-10">preconditioners, respectively -

    ILU for block-Jacobi and Additive Schwarz class="cmr-10">one-level preconditioners

    The local solver to be used with the smoother or one-level preconditioner (see @@ -2196,22 +2200,22 @@ 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 one-level preconditioner. In the multilevel @@ -2238,22 +2242,22 @@ class="cmr-10">respectively.

    ’SUB_OVR’

    integer

    Any integer -

    number ≥ 0

    1

    Number of overlap layers, for Additive Schwarz only.

    what

    		type

    val

    deault

    cots

    ’SUB_RESTR’

    character(len=*)

    ’HALO’ -

    ’NONE’

    ’HALO’

    Type of restriction operator, for Additive Schwarz only: ’NONE’ for neglecting it. -

    Note that HALO must be chosen for the @@ -2372,28 +2376,28 @@ class="cmr-10">its RAS variant.

    ’SUB_PROL’

    character(len=*)

    ’SUM’ -

    ’NONE’

    ’NONE’

    Type of prolongation operator, for Additive Schwarz only: ’ for neglecting them. -

    Note that ’SUMfor its RAS variant.

    ’SUB_FILLIN’

    integer

    Any integer -

    number ≥ 0

    0

    Fill-in level p of the incomplete LU @@ -2449,25 +2453,25 @@ class="cmr-10">factorizations.

    ’SUB_ILUTHRS’

    real(kind_parameter)

    Any real number ≥ 0

    0

    Drop tolerance t in the ILU(factorization.

    ’MUMPS_LOC_GLOB’

    character(len=*)

    ’LOCAL_SOLVER’ -

    ’GLOBAL_SOLVER’

    ’GLOBAL_SOLVER’

    Whether MUMPS should be used as a distributed solver, or as a serial solver acting @@ -2510,19 +2514,19 @@ class="cmr-10">process.

    ’MUMPS_IPAR_ENTRY’

    integer

    Any integer number

    0

    Set an entry in the MUMPS integer control array, as chosen via the argument.

    ’MUMPS_RPAR_ENTRY’

    real

    Any real number

    0

    Set an entry in the MUMPS real control array, as chosen via the Parameters defining the smoother or the details of the one-level -

    [next] [up]

    -

    diff --git a/docs/src/gettingstarted.tex b/docs/src/gettingstarted.tex index 5dba3495..04b07490 100644 --- a/docs/src/gettingstarted.tex +++ b/docs/src/gettingstarted.tex @@ -174,7 +174,7 @@ the corresponding codes are available in \verb|samples/simple/fileread/|. ! 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) + call P%init(ctxt,'ML',info) ! ! build the preconditioner call P%hierarchy_build(A,desc_A,info) @@ -184,8 +184,8 @@ the corresponding codes are available in \verb|samples/simple/fileread/|. ! 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) +! solve Ax=b with preconditioned FCG + call psb_krylov('FCG',A,P,b,x,tol,desc_A,info) ... ... ! ! deallocate the preconditioner @@ -229,7 +229,7 @@ stop ! 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) + call P%init(ctxt,'ML',info) ! ! build the preconditioner call P%hierarchy_build(A,desc_A,info) @@ -239,8 +239,8 @@ stop ! 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) +! solve Ax=b with preconditioned FCG + call psb_krylov('FCG',A,P,b,x,tol,desc_A,info) ... ... ! ! deallocate the preconditioner @@ -307,7 +307,7 @@ boundary conditions are also available in the directory \verb|samples/simple/pde ! 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%init(ctxt,'ML',info) call P%set('SMOOTHER_TYPE','BJAC',info) call P%set('COARSE_SOLVE','BJAC',info) call P%set('COARSE_SWEEPS',8,info) @@ -323,7 +323,7 @@ call P%smoothers_build(A,desc_A,info) ! 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%init(ctxt,'ML',info) call P%set('SMOOTHER_TYPE','BJAC',info) call P%set('COARSE_SOLVE','BJAC',info) call P%set('COARSE_SWEEPS',8,info) @@ -345,7 +345,7 @@ call P%smoothers_build(A,desc_A,info) !2 hybrid Gauss-Seidel sweeps as pre- and post-smoother, !and parallel flexible Conjugate Gradient coupled with the block-Jacobi !preconditioner having ILU(0) on the blocks as coarsest solver. -call P%init('ML',info) +call P%init(ctxt,'ML',info) call P%set('PAR_AGGR_ALG','COUPLED',info) call P%set('AGGR_TYPE','MATCHBOXP',info) call P%set('AGGR_SIZE',8,info) @@ -353,6 +353,8 @@ 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%set('COARSE_MAT','DIST',info) +call P%set('KRM_METHOD','FCG',info) call P%hierarchy_build(A,desc_A,info) call P%smoothers_build(A,desc_A,info) \end{minted} @@ -365,14 +367,16 @@ 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%init(ctxt,'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('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%set('COARSE_MAT','DIST',info) + call P%set('KRM_METHOD','FCG',info) call P%hierarchy_build(A,desc_A,info) call P%smoothers_build(A,desc_A,info) ... ... @@ -387,7 +391,7 @@ call P%set('AGGR_SIZE',8,info) \ifpdf \begin{minted}[breaklines=true,bgcolor=bg,fontsize=\small]{fortran} ! build a one-level RAS with overlap 2 and ILU(0) on the local blocks. -call P%init('AS',info) +call P%init(ctxt,'AS',info) call P%set('SUB_OVR',2,info) call P%build(A,desc_A,info) ... ... @@ -401,7 +405,7 @@ call P%build(A,desc_A,info) \begin{verbatim} ... ... ! set RAS with overlap 2 and ILU(0) on the local blocks - call P%init('AS',info) + call P%init(ctxt,'AS',info) call P%set('SUB_OVR',2,info) call P%bld(A,desc_A,info) ... ... diff --git a/docs/src/userinterface.tex b/docs/src/userinterface.tex index 2a496079..007a3469 100644 --- a/docs/src/userinterface.tex +++ b/docs/src/userinterface.tex @@ -176,9 +176,10 @@ Similar considerations apply to the point-Jacobi, Gauss-Seidel and block-Jacobi coarsest-level solvers, and shortcuts are available in this case too (see Table~\ref{tab:p_coarse_1}). \\ -\textbf{Remark 3.} Many of the coarsest-level solvers cannot be used -with both replicated and distributed coarsest-matrix layouts; -therefore, setting the solver after the layout may change the layout. +\textbf{Remark 3.} Many of the coarsest-level solvers apply to a +specific coarsest-matrix layout; +therefore, setting the solver after the layout may change the layout +to either distributed or replicated. Similarly, setting the layout after the solver may change the solver. More precisely, UMFPACK and SuperLU require the coarsest-level @@ -399,8 +400,14 @@ the parameter \texttt{ilev}.} \\ \fortinline|'COARSE_SOLVE'| & \fortinline|character(len=*)| & \fortinline|'MUMPS'| \par \fortinline|'UMF'| \par \fortinline|'SLU'| \par \fortinline|'SLUDIST'| \par - \fortinline|'JACOBI'| \par \fortinline|'GS'| \par \fortinline|'BJAC'| \par \fortinline|'KRM'| - \fortinline|'L1-JACOBI'| \par \fortinline|'L1-BJAC'| \par \fortinline|'L1-FBGS'| + \fortinline|'ILU'| \par + \fortinline|'JACOBI'| \par + \fortinline|'GS'| \par + \fortinline|'BJAC'| \par + \fortinline|'KRM'| \par + \fortinline|'L1-JACOBI'| \par + \fortinline|'L1-BJAC'| \par + \fortinline|'L1-FBGS'| & See~Note. & Solver used at the coarsest level: sequential LU from MUMPS, UMFPACK, or SuperLU diff --git a/samples/simple/pdegen/amg_dexample_ml.f90 b/samples/simple/pdegen/amg_dexample_ml.f90 index 64bdc4fc..c9c18fbd 100644 --- a/samples/simple/pdegen/amg_dexample_ml.f90 +++ b/samples/simple/pdegen/amg_dexample_ml.f90 @@ -38,7 +38,7 @@ ! File: amg_dexample_ml.f90 ! ! This sample program solves a linear system obtained by discretizing a -! PDE with Dirichlet BCs. The solver is CG, coupled with one of the +! PDE with Dirichlet BCs. The solver is FCG, coupled with one of the ! following multi-level preconditioner, as explained in Section 4.1 of ! the AMG4PSBLAS User's and Reference Guide: ! @@ -121,7 +121,8 @@ program amg_dexample_ml real(psb_dpk_) :: resmx, resmxp real(psb_dpk_) :: t1, t2, tprec character(len=5) :: afmt='CSR' - character(len=20) :: name, kmethod + character(len=20) :: name + character(len=20), parameter :: kmethod='FCG' ! initialize the parallel environment @@ -177,7 +178,6 @@ program amg_dexample_ml ! solver call P%init(ctxt,'ML',info) - kmethod = 'CG' case(2) @@ -188,15 +188,16 @@ program amg_dexample_ml call P%init(ctxt,'ML',info) call P%set('SMOOTHER_TYPE','BJAC',info) call P%set('COARSE_SOLVE','BJAC',info) + call P%set('COARSE_SUBSOLVE','ILU',info) call P%set('COARSE_SWEEPS',8,info) - kmethod = 'CG' case(3) - ! initialize a W-cycle preconditioner based on the coupled aggregation relying on matching, - ! with maximum size of aggregates equal to 8 and smoothed prolongators, - ! 2 hybrid forward/backward GS sweeps as pre/post-smoother, a distributed coarsest - ! matrix, and preconditioned Flexible Conjugate Gradient as coarsest-level solver + ! initialize a W-cycle preconditioner based on the coupled aggregation + ! relying on matching, with maximum size of aggregates equal to 8 + ! and smoothed prolongators, 2 hybrid forward/backward GS sweeps + ! as pre/post-smoother, a distributed coarsest matrix, + ! and preconditioned Flexible Conjugate Gradient as coarsest-level solver call P%init(ctxt,'ML',info) call P%set('PAR_AGGR_ALG','COUPLED',info) @@ -206,7 +207,7 @@ program amg_dexample_ml call P%set('SMOOTHER_SWEEPS',2,info) call P%set('COARSE_SOLVE','KRM',info) call P%set('COARSE_MAT','DIST',info) - kmethod = 'CG' + call P%set('KRM_METHOD','FCG',info) end select diff --git a/samples/simple/pdegen/amg_sexample_ml.f90 b/samples/simple/pdegen/amg_sexample_ml.f90 index 0f2734ea..e3d023e1 100644 --- a/samples/simple/pdegen/amg_sexample_ml.f90 +++ b/samples/simple/pdegen/amg_sexample_ml.f90 @@ -38,7 +38,7 @@ ! File: amg_sexample_ml.f90 ! ! This sample program solves a linear system obtained by discretizing a -! PDE with Dirichlet BCs. The solver is CG, coupled with one of the +! PDE with Dirichlet BCs. The solver is FCG, coupled with one of the ! following multi-level preconditioner, as explained in Section 4.1 of ! the AMG4PSBLAS User's and Reference Guide: ! @@ -121,7 +121,8 @@ program amg_sexample_ml real(psb_spk_) :: resmx, resmxp real(psb_dpk_) :: t1, t2, tprec character(len=5) :: afmt='CSR' - character(len=20) :: name, kmethod + character(len=20) :: name + character(len=20), parameter :: kmethod='FCG' ! initialize the parallel environment @@ -177,7 +178,6 @@ program amg_sexample_ml ! solver call P%init(ctxt,'ML',info) - kmethod = 'CG' case(2) @@ -188,15 +188,16 @@ program amg_sexample_ml call P%init(ctxt,'ML',info) call P%set('SMOOTHER_TYPE','BJAC',info) call P%set('COARSE_SOLVE','BJAC',info) + call P%set('COARSE_SUBSOLVE','ILU',info) call P%set('COARSE_SWEEPS',8,info) - kmethod = 'CG' case(3) - ! initialize a W-cycle preconditioner based on the coupled aggregation relying on matching, - ! with maximum size of aggregates equal to 8 and smoothed prolongators, - ! 2 hybrid forward/backward GS sweeps as pre/post-smoother, a distributed coarsest - ! matrix, and preconditioned Flexible Conjugate Gradient as coarsest-level solver + ! initialize a W-cycle preconditioner based on the coupled aggregation + ! relying on matching, with maximum size of aggregates equal to 8 + ! and smoothed prolongators, 2 hybrid forward/backward GS sweeps + ! as pre/post-smoother, a distributed coarsest matrix, + ! and preconditioned Flexible Conjugate Gradient as coarsest-level solver call P%init(ctxt,'ML',info) call P%set('PAR_AGGR_ALG','COUPLED',info) @@ -206,7 +207,7 @@ program amg_sexample_ml call P%set('SMOOTHER_SWEEPS',2,info) call P%set('COARSE_SOLVE','KRM',info) call P%set('COARSE_MAT','DIST',info) - kmethod = 'CG' + call P%set('KRM_METHOD','FCG',info) end select