!!$ !!$ Parallel Sparse BLAS v2.0 !!$ (C) Copyright 2006 Salvatore Filippone University of Rome Tor Vergata !!$ Alfredo Buttari University of Rome Tor Vergata !!$ !!$ 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. 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File: psb_krylov_mod.f90 ! Interfaces for Krylov subspace iterative methods. ! Module psb_krylov_mod interface psb_krylov module procedure psb_dkrylov, psb_zkrylov end interface interface psb_cg subroutine psb_dcg(a,prec,b,x,eps,& & desc_a,info,itmax,iter,err,itrace,istop) use psb_base_mod use psb_prec_mod type(psb_dspmat_type), intent(in) :: a type(psb_desc_type), intent(in) :: desc_a real(kind(1.d0)), intent(in) :: b(:) real(kind(1.d0)), intent(inout) :: x(:) real(kind(1.d0)), intent(in) :: eps type(psb_dprec_type), intent(in) :: prec integer, intent(out) :: info integer, optional, intent(in) :: itmax, itrace,istop integer, optional, intent(out) :: iter real(kind(1.d0)), optional, intent(out) :: err end subroutine psb_dcg end interface interface psb_bicg subroutine psb_dbicg(a,prec,b,x,eps,& & desc_a,info,itmax,iter,err,itrace,istop) use psb_base_mod use psb_prec_mod type(psb_dspmat_type), intent(in) :: a type(psb_desc_type), intent(in) :: desc_a real(kind(1.d0)), intent(in) :: b(:) real(kind(1.d0)), intent(inout) :: x(:) real(kind(1.d0)), intent(in) :: eps type(psb_dprec_type), intent(in) :: prec integer, intent(out) :: info integer, optional, intent(in) :: itmax, itrace,istop integer, optional, intent(out) :: iter real(kind(1.d0)), optional, intent(out) :: err end subroutine psb_dbicg end interface interface psb_bicgstab subroutine psb_dcgstab(a,prec,b,x,eps,& & desc_a,info,itmax,iter,err,itrace,istop) use psb_base_mod use psb_prec_mod type(psb_dspmat_type), intent(in) :: a type(psb_desc_type), intent(in) :: desc_a real(kind(1.d0)), intent(in) :: b(:) real(kind(1.d0)), intent(inout) :: x(:) real(kind(1.d0)), intent(in) :: eps type(psb_dprec_type), intent(in) :: prec integer, intent(out) :: info integer, optional, intent(in) :: itmax, itrace,istop integer, optional, intent(out) :: iter real(kind(1.d0)), optional, intent(out) :: err end subroutine psb_dcgstab subroutine psb_zcgstab(a,prec,b,x,eps,& & desc_a,info,itmax,iter,err,itrace,istop) use psb_base_mod use psb_prec_mod type(psb_zspmat_type), intent(in) :: a type(psb_desc_type), intent(in) :: desc_a complex(kind(1.d0)), intent(in) :: b(:) complex(kind(1.d0)), intent(inout) :: x(:) real(kind(1.d0)), intent(in) :: eps type(psb_zprec_type), intent(in) :: prec integer, intent(out) :: info integer, optional, intent(in) :: itmax, itrace,istop integer, optional, intent(out) :: iter real(kind(1.d0)), optional, intent(out) :: err end subroutine psb_zcgstab end interface interface psb_bicgstabl Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err, itrace,irst,istop) use psb_base_mod use psb_prec_mod Type(psb_dspmat_type), Intent(in) :: a Type(psb_desc_type), Intent(in) :: desc_a type(psb_dprec_type), intent(in) :: prec Real(Kind(1.d0)), Intent(in) :: b(:) Real(Kind(1.d0)), Intent(inout) :: x(:) Real(Kind(1.d0)), Intent(in) :: eps integer, intent(out) :: info Integer, Optional, Intent(in) :: itmax, itrace, irst,istop Integer, Optional, Intent(out) :: iter Real(Kind(1.d0)), Optional, Intent(out) :: err end subroutine psb_dcgstabl end interface interface psb_rgmres Subroutine psb_drgmres(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,irst,istop) use psb_base_mod use psb_prec_mod Type(psb_dspmat_type), Intent(in) :: a Type(psb_desc_type), Intent(in) :: desc_a type(psb_dprec_type), intent(in) :: prec Real(Kind(1.d0)), Intent(in) :: b(:) Real(Kind(1.d0)), Intent(inout) :: x(:) Real(Kind(1.d0)), Intent(in) :: eps integer, intent(out) :: info Integer, Optional, Intent(in) :: itmax, itrace, irst,istop Integer, Optional, Intent(out) :: iter Real(Kind(1.d0)), Optional, Intent(out) :: err end subroutine psb_drgmres Subroutine psb_zrgmres(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,irst,istop) use psb_base_mod use psb_prec_mod Type(psb_zspmat_type), Intent(in) :: a Type(psb_desc_type), Intent(in) :: desc_a type(psb_zprec_type), intent(in) :: prec complex(Kind(1.d0)), Intent(in) :: b(:) complex(Kind(1.d0)), Intent(inout) :: x(:) Real(Kind(1.d0)), Intent(in) :: eps integer, intent(out) :: info Integer, Optional, Intent(in) :: itmax, itrace, irst,istop Integer, Optional, Intent(out) :: iter Real(Kind(1.d0)), Optional, Intent(out) :: err end subroutine psb_zrgmres end interface interface psb_cgs subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) use psb_base_mod use psb_prec_mod type(psb_dspmat_type), intent(in) :: a type(psb_desc_type), intent(in) :: desc_a type(psb_dprec_type), intent(in) :: prec real(kind(1.d0)), intent(in) :: b(:) real(kind(1.d0)), intent(inout) :: x(:) real(kind(1.d0)), intent(in) :: eps integer, intent(out) :: info integer, optional, intent(in) :: itmax, itrace,istop integer, optional, intent(out) :: iter real(kind(1.d0)), optional, intent(out) :: err end subroutine psb_dcgs subroutine psb_zcgs(a,prec,b,x,eps,& & desc_a,info,itmax,iter,err,itrace,istop) use psb_base_mod use psb_prec_mod type(psb_zspmat_type), intent(in) :: a type(psb_desc_type), intent(in) :: desc_a complex(kind(1.d0)), intent(in) :: b(:) complex(kind(1.d0)), intent(inout) :: x(:) real(kind(1.d0)), intent(in) :: eps type(psb_zprec_type), intent(in) :: prec integer, intent(out) :: info integer, optional, intent(in) :: itmax, itrace,istop integer, optional, intent(out) :: iter real(kind(1.d0)), optional, intent(out) :: err end subroutine psb_zcgs end interface contains ! Subroutine: psb_dkrylov ! ! Front-end for the Krylov subspace iterations, real version ! ! Arguments: ! ! methd - character The specific method; can take the values: ! CG ! CGS ! BICG ! BICGSTAB ! BICGSTABL ! RGMRES ! ! a - type(psb_dspmat_type) Input: sparse matrix containing A. ! prec - type(psb_dprec_type) Input: preconditioner ! b - real,dimension(:) Input: vector containing the ! right hand side B ! x - real,dimension(:) Input/Output: vector containing the ! initial guess and final solution X. ! eps - real Input: Stopping tolerance; the iteration is ! stopped when the error ! estimate |err| <= eps ! desc_a - type(psb_desc_type). Input: The communication descriptor. ! info - integer. Output: Return code ! ! itmax - integer(optional) Input: maximum number of iterations to be ! performed. ! iter - integer(optional) Output: how many iterations have been ! performed. ! err - real (optional) Output: error estimate on exit ! itrace - integer(optional) Input: print an informational message ! with the error estimate every itrace ! iterations ! irst - integer(optional) Input: restart parameter for RGMRES and ! BICGSTAB(L) methods ! istop - integer(optional) Input: stopping criterion, or how ! to estimate the error. ! 1: err = |r|/|b| ! 2: err = |r|/(|a||x|+|b|) ! where r is the (preconditioned, recursive ! estimate of) residual ! Subroutine psb_dkrylov(method,a,prec,b,x,eps,desc_a,info,itmax,iter,err,itrace,irst,istop) use psb_base_mod use psb_prec_mod character(len=*) :: method Type(psb_dspmat_type), Intent(in) :: a Type(psb_desc_type), Intent(in) :: desc_a type(psb_dprec_type), intent(in) :: prec Real(Kind(1.d0)), Intent(in) :: b(:) Real(Kind(1.d0)), Intent(inout) :: x(:) Real(Kind(1.d0)), Intent(in) :: eps integer, intent(out) :: info Integer, Optional, Intent(in) :: itmax, itrace, irst,istop Integer, Optional, Intent(out) :: iter Real(Kind(1.d0)), Optional, Intent(out) :: err integer :: ictxt,me,np,err_act character(len=20) :: name info = 0 name = 'psb_krylov' call psb_erractionsave(err_act) ictxt=psb_cd_get_context(desc_a) call psb_info(ictxt, me, np) select case(toupper(method)) case('CG') call psb_cg(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) case('CGS') call psb_cgs(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) case('BICG') call psb_bicg(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) case('BICGSTAB') call psb_bicgstab(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) case('RGMRES') call psb_rgmres(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,irst,istop) case('BICGSTABL') call psb_bicgstabl(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,irst,istop) case default if (me==0) write(0,*) 'Warning: Unknown method ',method,& & ' in PSB_KRYLOV, defaulting to BiCGSTAB' call psb_bicgstab(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) end select if(info/=0) then call psb_errpush(info,name) goto 9999 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 end subroutine psb_dkrylov ! ! Subroutine: psb_zkrylov ! ! Front-end for the Krylov subspace iterations, complexversion ! ! Arguments: ! ! methd - character The specific method; can take the values: ! CGS ! BICGSTAB ! RGMRES ! ! a - type(psb_zspmat_type) Input: sparse matrix containing A. ! prec - type(psb_zprec_type) Input: preconditioner ! b - complex,dimension(:) Input: vector containing the ! right hand side B ! x - complex,dimension(:) Input/Output: vector containing the ! initial guess and final solution X. ! eps - real Input: Stopping tolerance; the iteration is ! stopped when the error ! estimate |err| <= eps ! ! desc_a - type(psb_desc_type). Input: The communication descriptor. ! info - integer. Output: Return code ! ! itmax - integer(optional) Input: maximum number of iterations to be ! performed. ! iter - integer(optional) Output: how many iterations have been ! performed. ! err - real (optional) Output: error estimate on exit ! itrace - integer(optional) Input: print an informational message ! with the error estimate every itrace ! iterations ! irst - integer(optional) Input: restart parameter for RGMRES and ! BICGSTAB(L) methods ! istop - integer(optional) Input: stopping criterion, or how ! to estimate the error. ! 1: err = |r|/|b| ! 2: err = |r|/(|a||x|+|b|) ! where r is the (preconditioned, recursive ! estimate of) residual ! Subroutine psb_zkrylov(method,a,prec,b,x,eps,desc_a,info,itmax,iter,err,itrace,irst,istop) use psb_base_mod use psb_prec_mod character(len=*) :: method Type(psb_zspmat_type), Intent(in) :: a Type(psb_desc_type), Intent(in) :: desc_a type(psb_zprec_type), intent(in) :: prec complex(Kind(1.d0)), Intent(in) :: b(:) complex(Kind(1.d0)), Intent(inout) :: x(:) Real(Kind(1.d0)), Intent(in) :: eps integer, intent(out) :: info Integer, Optional, Intent(in) :: itmax, itrace, irst,istop Integer, Optional, Intent(out) :: iter Real(Kind(1.d0)), Optional, Intent(out) :: err integer :: ictxt,me,np,err_act character(len=20) :: name info = 0 name = 'psb_krylov' call psb_erractionsave(err_act) ictxt=psb_cd_get_context(desc_a) call psb_info(ictxt, me, np) select case(toupper(method)) !!$ case('CG') !!$ call psb_cg(a,prec,b,x,eps,desc_a,info,& !!$ &itmax,iter,err,itrace,istop) case('CGS') call psb_cgs(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) !!$ case('BICG') !!$ call psb_bicg(a,prec,b,x,eps,desc_a,info,& !!$ &itmax,iter,err,itrace,istop) case('BICGSTAB') call psb_bicgstab(a,prec,b,x,eps,desc_a,info,& & itmax,iter,err,itrace,istop) case('RGMRES') call psb_rgmres(a,prec,b,x,eps,desc_a,info,& & itmax,iter,err,itrace,irst,istop) !!$ case('BICGSTABL') !!$ call psb_bicgstabl(a,prec,b,x,eps,desc_a,info,& !!$ &itmax,iter,err,itrace,irst,istop) case default if (me==0) write(0,*) 'Warning: Unknown method ',method,& & ' in PSB_KRYLOV, defaulting to BiCGSTAB' call psb_bicgstab(a,prec,b,x,eps,desc_a,info,& &itmax,iter,err,itrace,istop) end select if(info/=0) then call psb_errpush(info,name) goto 9999 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 end subroutine psb_zkrylov subroutine log_conv(methdname,me,itx,itrace,errnum,errden,eps) character(len=*), intent(in) :: methdname integer, intent(in) :: me, itx, itrace real(kind(1.d0)), intent(in) :: errnum, errden, eps character(len=*), parameter :: fmt='(a,i4,3(2x,es10.4))' if ((mod(itx,itrace)==0).and.(me == 0)) then write(*,fmt) methdname//': ',itx,errnum,eps*errden Endif end subroutine log_conv subroutine end_log(methdname,me,itx,errnum,errden,eps) character(len=*), intent(in) :: methdname integer, intent(in) :: me, itx real(kind(1.d0)), intent(in) :: errnum, errden, eps character(len=*), parameter :: fmt='(a,2x,es10.4,1x,a,1x,i4,1x,a)' character(len=*), parameter :: fmt1='(a,3(2x,es10.4))' if (me==0) then write(*,fmt) methdname//' failed to converge to ',eps,& & ' in ',ITX,' iterations. ' write(*,fmt1) 'Last iteration convergence indicators: ',& & errnum,eps*errden,errnum/errden end if end subroutine end_log end module psb_krylov_mod