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592 lines
18 KiB
Fortran
592 lines
18 KiB
Fortran
!!$
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!!$
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!!$ MLD2P4 version 2.0
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!!$ MultiLevel Domain Decomposition Parallel Preconditioners Package
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!!$ based on PSBLAS (Parallel Sparse BLAS version 3.0)
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!!$
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!!$ (C) Copyright 2008,2009,2010
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!!$
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!!$ Salvatore Filippone University of Rome Tor Vergata
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!!$ Alfredo Buttari CNRS-IRIT, Toulouse
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!!$ Pasqua D'Ambra ICAR-CNR, Naples
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!!$ Daniela di Serafino Second University of Naples
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!!$
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!!$ Redistribution and use in source and binary forms, with or without
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!!$ modification, are permitted provided that the following conditions
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!!$ are met:
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!!$ 1. Redistributions of source code must retain the above copyright
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!!$ notice, this list of conditions and the following disclaimer.
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!!$ 2. Redistributions in binary form must reproduce the above copyright
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!!$ notice, this list of conditions, and the following disclaimer in the
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!!$ documentation and/or other materials provided with the distribution.
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!!$ 3. The name of the MLD2P4 group or the names of its contributors may
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!!$ not be used to endorse or promote products derived from this
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!!$ software without specific written permission.
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!!$
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!!$ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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!!$ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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!!$ TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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!!$ PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE MLD2P4 GROUP OR ITS CONTRIBUTORS
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!!$ BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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!!$ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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!!$ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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!!$ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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!!$ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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!!$ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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!!$ POSSIBILITY OF SUCH DAMAGE.
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!!$
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!!$
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! File: mld_sexample_1lev.f90
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!
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! This sample program solves a linear system obtained by discretizing a
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! PDE with Dirichlet BCs. The solver is BiCGStab coupled with one of the
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! following multi-level preconditioner, as explained in Section 6.1 of
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! the MLD2P4 User's and Reference Guide:
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! - choice = 1, default multi-level Schwarz preconditioner (Sec. 6.1, Fig. 2)
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! - choice = 2, hybrid three-level Schwarz preconditioner (Sec. 6.1, Fig. 3)
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! - choice = 3, additive three-level Schwarz preconditioner (Sec. 6.1, Fig. 4)
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!
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! The PDE is a general second order equation in 3d
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!
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! b1 dd(u) b2 dd(u) b3 dd(u) a1 d(u) a2 d(u) a3 d(u)
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! - ------ - ------ - ------ - ----- - ------ - ------ + a4 u = 0
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! dxdx dydy dzdz dx dy dz
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!
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! with Dirichlet boundary conditions, on the unit cube 0<=x,y,z<=1.
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!
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! Example taken from:
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! C.T.Kelley
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! Iterative Methods for Linear and Nonlinear Equations
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! SIAM 1995
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!
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! In this sample program the index space of the discretized
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! computational domain is first numbered sequentially in a standard way,
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! then the corresponding vector is distributed according to a BLOCK
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! data distribution.
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!
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! Boundary conditions are set in a very simple way, by adding
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! equations of the form
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!
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! u(x,y) = exp(-x^2-y^2-z^2)
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!
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! Note that if a1=a2=a3=a4=0., the PDE is the well-known Laplace equation.
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!
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program mld_sexample_1lev
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use psb_base_mod
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use mld_prec_mod
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use psb_krylov_mod
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use psb_util_mod
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use data_input
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implicit none
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! sparse matrices
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type(psb_sspmat_type) :: A
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! descriptor of sparse matrices
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type(psb_desc_type):: desc_A
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! preconditioner
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type(mld_sprec_type) :: P
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! right-hand side, solution and residual vectors
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real(psb_spk_), allocatable , save :: b(:), x(:), r(:)
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! solver parameters
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real(psb_spk_) :: tol, err
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integer :: itmax, iter, itrace, istop
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! parallel environment parameters
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integer :: ictxt, iam, np
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! other variables
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integer :: i,info,j
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integer(psb_long_int_k_) :: amatsize, precsize, descsize
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integer :: idim, nlev, ierr, ircode
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real(psb_dpk_) :: t1, t2, tprec
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real(psb_spk_) :: resmx, resmxp
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character(len=20) :: name
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! initialize the parallel environment
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call psb_init(ictxt)
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call psb_info(ictxt,iam,np)
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if (iam < 0) then
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! This should not happen, but just in case
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call psb_exit(ictxt)
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stop
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endif
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name='mld_sexample_ml'
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if(psb_get_errstatus() /= 0) goto 9999
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info=psb_success_
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call psb_set_errverbosity(2)
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!
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! Hello world
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!
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if (iam == psb_root_) then
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write(*,*) 'Welcome to MLD2P4 version: ',mld_version_string_
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write(*,*) 'This is the ',trim(name),' sample program'
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end if
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! get parameters
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call get_parms(ictxt,idim,itmax,tol)
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! allocate and fill in the coefficient matrix, rhs and initial guess
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call psb_barrier(ictxt)
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t1 = psb_wtime()
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call create_matrix(idim,a,b,x,desc_a,ictxt,info)
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call psb_barrier(ictxt)
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t2 = psb_wtime() - t1
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if(info /= psb_success_) then
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info=psb_err_from_subroutine_
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call psb_errpush(info,name)
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goto 9999
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end if
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if (iam == psb_root_) write(*,'("Overall matrix creation time : ",es12.5)')t2
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if (iam == psb_root_) write(*,'(" ")')
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! set RAS with overlap 2 and ILU(0) on the local blocks
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call mld_precinit(P,'AS',info)
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call mld_precset(P,mld_sub_ovr_,2,info)
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! build the preconditioner
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call psb_barrier(ictxt)
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t1 = psb_wtime()
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call mld_precbld(A,desc_A,P,info)
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tprec = psb_wtime()-t1
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call psb_amx(ictxt, tprec)
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if (info /= psb_success_) then
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call psb_errpush(psb_err_from_subroutine_,name,a_err='psb_precbld')
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goto 9999
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end if
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! set the initial guess
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call psb_geall(x,desc_A,info)
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x(:) =0.0
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call psb_geasb(x,desc_A,info)
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! solve Ax=b with preconditioned BiCGSTAB
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call psb_barrier(ictxt)
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t1 = psb_wtime()
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call psb_krylov('BICGSTAB',A,P,b,x,tol,desc_A,info,itmax,iter,err,itrace=1,istop=2)
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t2 = psb_wtime() - t1
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call psb_amx(ictxt,t2)
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call psb_geall(r,desc_A,info)
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r(:) =0.0
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call psb_geasb(r,desc_A,info)
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call psb_geaxpby(sone,b,szero,r,desc_A,info)
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call psb_spmm(-sone,A,x,sone,r,desc_A,info)
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call psb_genrm2s(resmx,r,desc_A,info)
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call psb_geamaxs(resmxp,r,desc_A,info)
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amatsize = a%sizeof()
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descsize = desc_a%sizeof()
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precsize = p%sizeof()
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call psb_sum(ictxt,amatsize)
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call psb_sum(ictxt,descsize)
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call psb_sum(ictxt,precsize)
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call mld_precdescr(P,info)
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if (iam == psb_root_) then
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write(*,'(" ")')
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write(*,'("Matrix from PDE example")')
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write(*,'("Computed solution on ",i8," processors")')np
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write(*,'("Iterations to convergence : ",i6)')iter
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write(*,'("Error estimate on exit : ",es12.5)')err
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write(*,'("Time to build prec. : ",es12.5)')tprec
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write(*,'("Time to solve system : ",es12.5)')t2
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write(*,'("Time per iteration : ",es12.5)')t2/(iter)
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write(*,'("Total time : ",es12.5)')t2+tprec
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write(*,'("Residual 2-norm : ",es12.5)')resmx
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write(*,'("Residual inf-norm : ",es12.5)')resmxp
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write(*,'("Total memory occupation for A : ",i12)')amatsize
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write(*,'("Total memory occupation for DESC_A : ",i12)')descsize
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write(*,'("Total memory occupation for PREC : ",i12)')precsize
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end if
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call psb_gefree(b, desc_A,info)
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call psb_gefree(x, desc_A,info)
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call psb_spfree(A, desc_A,info)
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call mld_precfree(P,info)
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call psb_cdfree(desc_A,info)
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9999 continue
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if(info /= psb_success_) then
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call psb_error(ictxt)
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end if
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call psb_exit(ictxt)
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stop
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contains
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!
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! get parameters from standard input
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!
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subroutine get_parms(ictxt,idim,itmax,tol)
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use psb_base_mod
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implicit none
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integer :: idim, ictxt, itmax
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real(psb_spk_) :: tol
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integer :: iam, np
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call psb_info(ictxt,iam,np)
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if (iam == psb_root_) then
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! read input parameters
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call read_data(idim,5)
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call read_data(itmax,5)
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call read_data(tol,5)
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end if
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call psb_bcast(ictxt,idim)
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call psb_bcast(ictxt,itmax)
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call psb_bcast(ictxt,tol)
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end subroutine get_parms
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!
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! subroutine to allocate and fill in the coefficient matrix and
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! the rhs
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!
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subroutine create_matrix(idim,a,b,xv,desc_a,ictxt,info)
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!
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! Discretize the partial diferential equation
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!
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! b1 dd(u) b2 dd(u) b3 dd(u) a1 d(u) a2 d(u) a3 d(u)
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! - ------ - ------ - ------ - ----- - ------ - ------ + a4 u = 0
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! dxdx dydy dzdz dx dy dz
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!
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! with Dirichlet boundary conditions, on the unit cube 0<=x,y,z<=1.
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!
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! Boundary conditions are set in a very simple way, by adding
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! equations of the form
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!
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! u(x,y) = exp(-x^2-y^2-z^2)
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!
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! Note that if a1=a2=a3=a4=0., the PDE is the well-known Laplace equation.
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!
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use psb_base_mod
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implicit none
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integer :: idim
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integer, parameter :: nb=20
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real(psb_spk_), allocatable :: b(:),xv(:)
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type(psb_desc_type) :: desc_a
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integer :: ictxt, info
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character :: afmt*5
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type(psb_sspmat_type) :: a
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real(psb_spk_) :: zt(nb),x,y,z
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integer :: m,n,nnz,glob_row,nlr,i,ii,ib,k
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integer :: ix,iy,iz,ia,indx_owner, ipoints
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integer :: np, iam, nr, nt
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integer :: element
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integer, allocatable :: irow(:),icol(:),myidx(:)
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real(psb_spk_), allocatable :: val(:)
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! deltah dimension of each grid cell
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! deltat discretization time
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real(psb_spk_) :: deltah, deltah2
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real(psb_spk_),parameter :: rhs=0.0,one=1.0,zero=0.0
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real(psb_dpk_) :: t0, t1, t2, t3, tasb, talc, ttot, tgen
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real(psb_spk_) :: a1, a2, a3, a4, b1, b2, b3
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external :: a1, a2, a3, a4, b1, b2, b3
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integer :: err_act
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character(len=20) :: name, ch_err
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info = psb_success_
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name = 'create_matrix'
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call psb_erractionsave(err_act)
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call psb_info(ictxt, iam, np)
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deltah = 1.d0/(idim-1)
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deltah2 = deltah*deltah
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! initialize array descriptor and sparse matrix storage. provide an
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! estimate of the number of non zeroes
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ipoints=idim-2
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m = ipoints*ipoints*ipoints
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n = m
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nnz = ((n*9)/(np))
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if(iam == psb_root_) write(psb_out_unit,'("Generating Matrix (size=",i0,")...")')n
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!
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! Using a simple BLOCK distribution.
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!
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nt = (m+np-1)/np
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nr = max(0,min(nt,m-(iam*nt)))
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nt = nr
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call psb_sum(ictxt,nt)
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if (nt /= m) write(psb_err_unit,*) iam, 'Initialization error ',nr,nt,m
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call psb_barrier(ictxt)
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t0 = psb_wtime()
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call psb_cdall(ictxt,desc_a,info,nl=nr)
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if (info == psb_success_) call psb_spall(a,desc_a,info,nnz=nnz)
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! define rhs from boundary conditions; also build initial guess
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if (info == psb_success_) call psb_geall(b,desc_a,info)
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if (info == psb_success_) call psb_geall(xv,desc_a,info)
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nlr = psb_cd_get_local_rows(desc_a)
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call psb_barrier(ictxt)
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talc = psb_wtime()-t0
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if (info /= psb_success_) then
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info=psb_err_from_subroutine_
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ch_err='allocation rout.'
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call psb_errpush(info,name,a_err=ch_err)
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goto 9999
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end if
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! we build an auxiliary matrix consisting of one row at a
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! time; just a small matrix. might be extended to generate
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! a bunch of rows per call.
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!
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allocate(val(20*nb),irow(20*nb),&
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&icol(20*nb),myidx(nlr),stat=info)
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if (info /= psb_success_ ) then
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info=psb_err_alloc_dealloc_
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call psb_errpush(info,name)
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goto 9999
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endif
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do i=1,nlr
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myidx(i) = i
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end do
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call psb_loc_to_glob(myidx,desc_a,info)
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! loop over rows belonging to current process in a block
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! distribution.
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call psb_barrier(ictxt)
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t1 = psb_wtime()
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do ii=1, nlr,nb
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ib = min(nb,nlr-ii+1)
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element = 1
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do k=1,ib
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i=ii+k-1
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! local matrix pointer
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glob_row=myidx(i)
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! compute gridpoint coordinates
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if (mod(glob_row,ipoints*ipoints) == 0) then
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ix = glob_row/(ipoints*ipoints)
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else
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ix = glob_row/(ipoints*ipoints)+1
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endif
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if (mod((glob_row-(ix-1)*ipoints*ipoints),ipoints) == 0) then
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iy = (glob_row-(ix-1)*ipoints*ipoints)/ipoints
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else
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iy = (glob_row-(ix-1)*ipoints*ipoints)/ipoints+1
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endif
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iz = glob_row-(ix-1)*ipoints*ipoints-(iy-1)*ipoints
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! x, y, x coordinates
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x=ix*deltah
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y=iy*deltah
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z=iz*deltah
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! check on boundary points
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zt(k) = 0.d0
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! internal point: build discretization
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!
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! term depending on (x-1,y,z)
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!
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if (ix == 1) then
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val(element) = -b1(x,y,z)/deltah2-a1(x,y,z)/deltah
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zt(k) = exp(-x**2-y**2-z**2)*(-val(element))
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else
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val(element) = -b1(x,y,z)/deltah2-a1(x,y,z)/deltah
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icol(element) = (ix-2)*ipoints*ipoints+(iy-1)*ipoints+(iz)
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irow(element) = glob_row
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element = element+1
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endif
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! term depending on (x,y-1,z)
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if (iy == 1) then
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val(element) = -b2(x,y,z)/deltah2-a2(x,y,z)/deltah
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zt(k) = exp(-x**2-y**2-z**2)*exp(-x)*(-val(element))
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else
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val(element) = -b2(x,y,z)/deltah2-a2(x,y,z)/deltah
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icol(element) = (ix-1)*ipoints*ipoints+(iy-2)*ipoints+(iz)
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irow(element) = glob_row
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element = element+1
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endif
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! term depending on (x,y,z-1)
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if (iz == 1) then
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val(element)=-b3(x,y,z)/deltah2-a3(x,y,z)/deltah
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zt(k) = exp(-x**2-y**2-z**2)*exp(-x)*(-val(element))
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else
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val(element)=-b3(x,y,z)/deltah2-a3(x,y,z)/deltah
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icol(element) = (ix-1)*ipoints*ipoints+(iy-1)*ipoints+(iz-1)
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irow(element) = glob_row
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element = element+1
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endif
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! term depending on (x,y,z)
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val(element)=(2*b1(x,y,z) + 2*b2(x,y,z) + 2*b3(x,y,z))/deltah2&
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& + (a1(x,y,z) + a2(x,y,z) + a3(x,y,z)+ a4(x,y,z))/deltah
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icol(element) = (ix-1)*ipoints*ipoints+(iy-1)*ipoints+(iz)
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irow(element) = glob_row
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element = element+1
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! term depending on (x,y,z+1)
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if (iz == ipoints) then
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val(element)=-b1(x,y,z)/deltah2
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zt(k) = exp(-x**2-y**2-z**2)*exp(-x)*(-val(element))
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else
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val(element)=-b1(x,y,z)/deltah2
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icol(element) = (ix-1)*ipoints*ipoints+(iy-1)*ipoints+(iz+1)
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irow(element) = glob_row
|
|
element = element+1
|
|
endif
|
|
! term depending on (x,y+1,z)
|
|
if (iy == ipoints) then
|
|
val(element)=-b2(x,y,z)/deltah2
|
|
zt(k) = exp(-x**2-y**2-z**2)*exp(-x)*(-val(element))
|
|
else
|
|
val(element)=-b2(x,y,z)/deltah2
|
|
icol(element) = (ix-1)*ipoints*ipoints+(iy)*ipoints+(iz)
|
|
irow(element) = glob_row
|
|
element = element+1
|
|
endif
|
|
! term depending on (x+1,y,z)
|
|
if (ix==ipoints) then
|
|
val(element)=-b3(x,y,z)/deltah2
|
|
zt(k) = exp(-y**2-z**2)*exp(-x)*(-val(element))
|
|
else
|
|
val(element)=-b3(x,y,z)/deltah2
|
|
icol(element) = (ix)*ipoints*ipoints+(iy-1)*ipoints+(iz)
|
|
irow(element) = glob_row
|
|
element = element+1
|
|
endif
|
|
|
|
end do
|
|
call psb_spins(element-1,irow,icol,val,a,desc_a,info)
|
|
if(info /= psb_success_) exit
|
|
call psb_geins(ib,myidx(ii:ii+ib-1),zt(1:ib),b,desc_a,info)
|
|
if(info /= psb_success_) exit
|
|
zt(:)=0.d0
|
|
call psb_geins(ib,myidx(ii:ii+ib-1),zt(1:ib),xv,desc_a,info)
|
|
if(info /= psb_success_) exit
|
|
end do
|
|
|
|
tgen = psb_wtime()-t1
|
|
if(info /= psb_success_) then
|
|
info=psb_err_from_subroutine_
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
end if
|
|
|
|
deallocate(val,irow,icol)
|
|
|
|
call psb_barrier(ictxt)
|
|
t1 = psb_wtime()
|
|
call psb_cdasb(desc_a,info)
|
|
if (info == psb_success_) &
|
|
& call psb_spasb(a,desc_a,info,dupl=psb_dupl_err_)
|
|
call psb_barrier(ictxt)
|
|
if(info /= psb_success_) then
|
|
info=psb_err_from_subroutine_
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
end if
|
|
call psb_geasb(b,desc_a,info)
|
|
call psb_geasb(xv,desc_a,info)
|
|
if(info /= psb_success_) then
|
|
info=psb_err_from_subroutine_
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
end if
|
|
tasb = psb_wtime()-t1
|
|
call psb_barrier(ictxt)
|
|
ttot = psb_wtime() - t0
|
|
|
|
call psb_amx(ictxt,talc)
|
|
call psb_amx(ictxt,tgen)
|
|
call psb_amx(ictxt,tasb)
|
|
call psb_amx(ictxt,ttot)
|
|
if(iam == psb_root_) then
|
|
write(*,'("The matrix has been generated and assembled in ",a3," format.")')&
|
|
& a%get_fmt()
|
|
write(*,'("-allocation time : ",es12.5)') talc
|
|
write(*,'("-coeff. gen. time : ",es12.5)') tgen
|
|
write(*,'("-assembly time : ",es12.5)') tasb
|
|
write(*,'("-total time : ",es12.5)') ttot
|
|
|
|
end if
|
|
call psb_erractionrestore(err_act)
|
|
return
|
|
|
|
9999 continue
|
|
call psb_erractionrestore(err_act)
|
|
if (err_act == psb_act_abort_) then
|
|
call psb_error(ictxt)
|
|
return
|
|
end if
|
|
return
|
|
end subroutine create_matrix
|
|
end program mld_sexample_1lev
|
|
!
|
|
! functions parametrizing the differential equation
|
|
!
|
|
function a1(x,y,z)
|
|
use psb_base_mod, only : psb_spk_
|
|
real(psb_spk_) :: a1
|
|
real(psb_spk_) :: x,y,z
|
|
!a1=1.e0
|
|
a1=0.e0
|
|
end function a1
|
|
function a2(x,y,z)
|
|
use psb_base_mod, only : psb_spk_
|
|
real(psb_spk_) :: a2
|
|
real(psb_spk_) :: x,y,z
|
|
!a2=2.e1*y
|
|
a2=0.e0
|
|
end function a2
|
|
function a3(x,y,z)
|
|
use psb_base_mod, only : psb_spk_
|
|
real(psb_spk_) :: a3
|
|
real(psb_spk_) :: x,y,z
|
|
!a3=1.e0
|
|
a3=0.e0
|
|
end function a3
|
|
function a4(x,y,z)
|
|
use psb_base_mod, only : psb_spk_
|
|
real(psb_spk_) :: a4
|
|
real(psb_spk_) :: x,y,z
|
|
!a4=1.e0
|
|
a4=0.e0
|
|
end function a4
|
|
function b1(x,y,z)
|
|
use psb_base_mod, only : psb_spk_
|
|
real(psb_spk_) :: b1
|
|
real(psb_spk_) :: x,y,z
|
|
b1=1.e0
|
|
end function b1
|
|
function b2(x,y,z)
|
|
use psb_base_mod, only : psb_spk_
|
|
real(psb_spk_) :: b2
|
|
real(psb_spk_) :: x,y,z
|
|
b2=1.e0
|
|
end function b2
|
|
function b3(x,y,z)
|
|
use psb_base_mod, only : psb_spk_
|
|
real(psb_spk_) :: b3
|
|
real(psb_spk_) :: x,y,z
|
|
b3=1.e0
|
|
end function b3
|