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C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_jfnk.F,v 1.25 2014/02/07 14:27:21 mlosch Exp $ |
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C $Name: $ |
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|
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#include "SEAICE_OPTIONS.h" |
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|
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C-- File seaice_jfnk.F: seaice jfnk dynamical solver S/R: |
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C-- Contents |
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C-- o SEAICE_JFNK |
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C-- o SEAICE_JFNK_UPDATE |
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|
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CBOP |
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C !ROUTINE: SEAICE_JFNK |
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C !INTERFACE: |
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SUBROUTINE SEAICE_JFNK( myTime, myIter, myThid ) |
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|
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C !DESCRIPTION: \bv |
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C *==========================================================* |
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C | SUBROUTINE SEAICE_JFNK |
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C | o Ice dynamics using a Jacobian-free Newton-Krylov solver |
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C | following J.-F. Lemieux et al. Improving the numerical |
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C | convergence of viscous-plastic sea ice models with the |
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C | Jacobian-free Newton-Krylov method. J. Comp. Phys. 229, |
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C | 2840-2852 (2010). |
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C | o The logic follows JFs code. |
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C *==========================================================* |
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C | written by Martin Losch, Oct 2012 |
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C *==========================================================* |
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C \ev |
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|
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C !USES: |
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IMPLICIT NONE |
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|
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C === Global variables === |
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "DYNVARS.h" |
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#include "GRID.h" |
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#include "SEAICE_SIZE.h" |
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#include "SEAICE_PARAMS.h" |
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#include "SEAICE.h" |
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|
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#ifdef ALLOW_AUTODIFF_TAMC |
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# include "tamc.h" |
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#endif |
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|
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C !INPUT/OUTPUT PARAMETERS: |
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C === Routine arguments === |
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C myTime :: Simulation time |
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C myIter :: Simulation timestep number |
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C myThid :: my Thread Id. number |
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_RL myTime |
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INTEGER myIter |
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INTEGER myThid |
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|
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#ifdef SEAICE_ALLOW_JFNK |
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C !FUNCTIONS: |
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LOGICAL DIFFERENT_MULTIPLE |
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EXTERNAL DIFFERENT_MULTIPLE |
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|
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C !LOCAL VARIABLES: |
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C === Local variables === |
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C i,j,bi,bj :: loop indices |
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INTEGER i,j,bi,bj |
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C loop indices |
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INTEGER newtonIter |
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INTEGER krylovIter, krylovFails |
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INTEGER totalKrylovItersLoc, totalNewtonItersLoc |
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C FGMRES flag that determines amount of output messages of fgmres |
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INTEGER iOutFGMRES |
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C FGMRES flag that indicates what fgmres wants us to do next |
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INTEGER iCode |
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_RL JFNKresidual |
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_RL JFNKresidualKm1 |
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C parameters to compute convergence criterion |
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_RL JFNKgamma_lin |
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_RL FGMRESeps |
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_RL JFNKtol |
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C backward differences extrapolation factors |
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_RL bdfFac, bdfAlpha |
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C |
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_RL recip_deltaT |
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LOGICAL JFNKconverged, krylovConverged |
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LOGICAL writeNow |
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CHARACTER*(MAX_LEN_MBUF) msgBuf |
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|
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C u/vIceRes :: residual of sea-ice momentum equations |
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_RL uIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL vIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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C extra time level required for backward difference time stepping |
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_RL duIcNm1(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL dvIcNm1(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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C du/vIce :: ice velocity increment to be added to u/vIce |
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_RL duIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL dvIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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C precomputed (= constant per Newton iteration) versions of |
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C zeta, eta, and DWATN, press |
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_RL zetaPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL etaPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL etaZPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL dwatPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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CEOP |
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|
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C Initialise |
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newtonIter = 0 |
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krylovFails = 0 |
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totalKrylovItersLoc = 0 |
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JFNKconverged = .FALSE. |
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JFNKtol = 0. _d 0 |
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JFNKresidual = 0. _d 0 |
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JFNKresidualKm1 = 0. _d 0 |
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FGMRESeps = 0. _d 0 |
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recip_deltaT = 1. _d 0 / SEAICE_deltaTdyn |
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|
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iOutFGMRES=0 |
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C with iOutFgmres=1, seaice_fgmres prints the residual at each iteration |
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IF ( debugLevel.GE.debLevC .AND. |
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& DIFFERENT_MULTIPLE( SEAICE_monFreq, myTime, deltaTClock ) ) |
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& iOutFGMRES=1 |
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|
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C backward difference extrapolation factors |
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bdfFac = 0. _d 0 |
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IF ( SEAICEuseBDF2 ) THEN |
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IF ( myIter.EQ.nIter0 .AND. SEAICEmomStartBDF.EQ.0 ) THEN |
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bdfFac = 0. _d 0 |
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ELSE |
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bdfFac = 0.5 _d 0 |
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ENDIF |
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ENDIF |
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bdfAlpha = 1. _d 0 + bdfFac |
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|
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DO bj=myByLo(myThid),myByHi(myThid) |
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DO bi=myBxLo(myThid),myBxHi(myThid) |
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DO J=1-OLy,sNy+OLy |
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DO I=1-OLx,sNx+OLx |
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uIceRes(I,J,bi,bj) = 0. _d 0 |
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vIceRes(I,J,bi,bj) = 0. _d 0 |
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duIce (I,J,bi,bj) = 0. _d 0 |
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dvIce (I,J,bi,bj) = 0. _d 0 |
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ENDDO |
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ENDDO |
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C cycle ice velocities |
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DO J=1-OLy,sNy+OLy |
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DO I=1-OLx,sNx+OLx |
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duIcNm1(I,J,bi,bj) = uIce(I,J,bi,bj) * bdfAlpha |
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& + ( uIce(I,J,bi,bj) - uIceNm1(I,J,bi,bj) ) * bdfFac |
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dvIcNm1(I,J,bi,bj) = vIce(I,J,bi,bj) * bdfAlpha |
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& + ( vIce(I,J,bi,bj) - vIceNm1(I,J,bi,bj) ) * bdfFac |
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uIceNm1(I,J,bi,bj) = uIce(I,J,bi,bj) |
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vIceNm1(I,J,bi,bj) = vIce(I,J,bi,bj) |
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ENDDO |
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ENDDO |
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C As long as IMEX is not properly implemented leave this commented out |
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CML IF ( .NOT.SEAICEuseIMEX ) THEN |
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C Compute things that do no change during the Newton iteration: |
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C sea-surface tilt and wind stress: |
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C FORCEX/Y0 - mass*(1.5*u/vIceNm1+0.5*(u/vIceNm1-u/vIceNm2))/deltaT |
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DO J=1-OLy,sNy+OLy |
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DO I=1-OLx,sNx+OLx |
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FORCEX(I,J,bi,bj) = FORCEX0(I,J,bi,bj) |
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& + seaiceMassU(I,J,bi,bj)*duIcNm1(I,J,bi,bj)*recip_deltaT |
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FORCEY(I,J,bi,bj) = FORCEY0(I,J,bi,bj) |
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& + seaiceMassV(I,J,bi,bj)*dvIcNm1(I,J,bi,bj)*recip_deltaT |
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ENDDO |
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ENDDO |
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CML ENDIF |
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ENDDO |
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ENDDO |
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C Start nonlinear Newton iteration: outer loop iteration |
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DO WHILE ( newtonIter.LT.SEAICEnewtonIterMax .AND. |
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& .NOT.JFNKconverged ) |
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newtonIter = newtonIter + 1 |
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C Compute initial residual F(u), (includes computation of global |
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C variables DWATN, zeta, and eta) |
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IF ( newtonIter .EQ. 1 ) CALL SEAICE_JFNK_UPDATE( |
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I duIce, dvIce, |
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U uIce, vIce, JFNKresidual, |
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O uIceRes, vIceRes, |
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I newtonIter, myTime, myIter, myThid ) |
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C local copies of precomputed coefficients that are to stay |
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C constant for the preconditioner |
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DO bj=myByLo(myThid),myByHi(myThid) |
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DO bi=myBxLo(myThid),myBxHi(myThid) |
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DO j=1-OLy,sNy+OLy |
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DO i=1-OLx,sNx+OLx |
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zetaPre(I,J,bi,bj) = zeta(I,J,bi,bj) |
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etaPre(I,J,bi,bj) = eta(I,J,bi,bj) |
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etaZPre(I,J,bi,bj) = etaZ(I,J,bi,bj) |
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dwatPre(I,J,bi,bj) = DWATN(I,J,bi,bj) |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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C compute convergence criterion for linear preconditioned FGMRES |
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JFNKgamma_lin = JFNKgamma_lin_max |
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IF ( newtonIter.GT.1.AND.newtonIter.LE.SEAICE_JFNK_tolIter |
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& .AND.JFNKresidual.LT.JFNKres_t ) THEN |
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C Eisenstat and Walker (1996), eq.(2.6) |
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JFNKgamma_lin = SEAICE_JFNKphi |
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& *( JFNKresidual/JFNKresidualKm1 )**SEAICE_JFNKalpha |
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JFNKgamma_lin = min(JFNKgamma_lin_max, JFNKgamma_lin) |
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JFNKgamma_lin = max(JFNKgamma_lin_min, JFNKgamma_lin) |
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ENDIF |
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C save the residual for the next iteration |
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JFNKresidualKm1 = JFNKresidual |
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|
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C The Krylov iteration using FGMRES, the preconditioner is LSOR |
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C for now. The code is adapted from SEAICE_LSR, but heavily stripped |
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C down. |
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C krylovIter is mapped into "its" in seaice_fgmres and is incremented |
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C in that routine |
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krylovIter = 0 |
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iCode = 0 |
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|
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JFNKconverged = JFNKresidual.LT.JFNKtol |
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|
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C do Krylov loop only if convergence is not reached |
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|
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IF ( .NOT.JFNKconverged ) THEN |
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|
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C start Krylov iteration (FGMRES) |
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|
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krylovConverged = .FALSE. |
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FGMRESeps = JFNKgamma_lin * JFNKresidual |
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DO WHILE ( .NOT.krylovConverged ) |
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C solution vector sol = du/vIce |
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C residual vector (rhs) Fu = u/vIceRes |
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C output work vectors wk1, -> input work vector wk2 |
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|
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CALL SEAICE_FGMRES_DRIVER( |
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I uIceRes, vIceRes, |
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U duIce, dvIce, iCode, |
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I FGMRESeps, iOutFGMRES, |
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I newtonIter, krylovIter, myTime, myIter, myThid ) |
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C FGMRES returns iCode either asking for an new preconditioned vector |
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C or product of matrix (Jacobian) times vector. For iCode = 0, terminate |
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C iteration |
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IF (iCode.EQ.1) THEN |
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C Call preconditioner |
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IF ( SOLV_MAX_ITERS .GT. 0 ) |
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& CALL SEAICE_PRECONDITIONER( |
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U duIce, dvIce, |
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I zetaPre, etaPre, etaZpre, dwatPre, |
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I newtonIter, krylovIter, myTime, myIter, myThid ) |
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ELSEIF (iCode.GE.2) THEN |
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C Compute Jacobian times vector |
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CALL SEAICE_JACVEC( |
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I uIce, vIce, uIceRes, vIceRes, |
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U duIce, dvIce, |
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I newtonIter, krylovIter, myTime, myIter, myThid ) |
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ENDIF |
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krylovConverged = iCode.EQ.0 |
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C End of Krylov iterate |
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ENDDO |
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totalKrylovItersLoc = totalKrylovItersLoc + krylovIter |
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C some output diagnostics |
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IF ( debugLevel.GE.debLevA ) THEN |
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_BEGIN_MASTER( myThid ) |
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totalNewtonItersLoc = |
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& SEAICEnewtonIterMax*(myIter-nIter0)+newtonIter |
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WRITE(msgBuf,'(2A,2(1XI6),2E12.5)') |
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& ' S/R SEAICE_JFNK: Newton iterate / total, ', |
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& 'JFNKgamma_lin, initial norm = ', |
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& newtonIter, totalNewtonItersLoc, |
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& JFNKgamma_lin,JFNKresidual |
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CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
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& SQUEEZE_RIGHT, myThid ) |
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WRITE(msgBuf,'(3(A,I6))') |
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& ' S/R SEAICE_JFNK: Newton iterate / total = ',newtonIter, |
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& ' / ', totalNewtonItersLoc, |
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& ', Nb. of FGMRES iterations = ', krylovIter |
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CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
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& SQUEEZE_RIGHT, myThid ) |
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_END_MASTER( myThid ) |
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ENDIF |
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IF ( krylovIter.EQ.SEAICEkrylovIterMax ) THEN |
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krylovFails = krylovFails + 1 |
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ENDIF |
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C Set the stopping criterion for the Newton iteration and the |
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C criterion for the transition from accurate to approximate FGMRES |
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IF ( newtonIter .EQ. 1 ) THEN |
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JFNKtol=JFNKgamma_nonlin*JFNKresidual |
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IF ( JFNKres_tFac .NE. UNSET_RL ) |
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& JFNKres_t = JFNKresidual * JFNKres_tFac |
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ENDIF |
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C Update linear solution vector and return to Newton iteration |
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C Do a linesearch if necessary, and compute a new residual. |
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C Note that it should be possible to do the following operations |
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C at the beginning of the Newton iteration, thereby saving us from |
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C the extra call of seaice_jfnk_update, but unfortunately that |
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C changes the results, so we leave the stuff here for now. |
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CALL SEAICE_JFNK_UPDATE( |
293 |
I duIce, dvIce, |
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U uIce, vIce, JFNKresidual, |
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O uIceRes, vIceRes, |
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I newtonIter, myTime, myIter, myThid ) |
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C reset du/vIce here instead of setting sol = 0 in seaice_fgmres_driver |
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DO bj=myByLo(myThid),myByHi(myThid) |
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DO bi=myBxLo(myThid),myBxHi(myThid) |
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DO J=1-OLy,sNy+OLy |
301 |
DO I=1-OLx,sNx+OLx |
302 |
duIce(I,J,bi,bj)= 0. _d 0 |
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dvIce(I,J,bi,bj)= 0. _d 0 |
304 |
ENDDO |
305 |
ENDDO |
306 |
ENDDO |
307 |
ENDDO |
308 |
ENDIF |
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C end of Newton iterate |
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ENDDO |
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|
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C-- Output diagnostics |
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|
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IF ( SEAICE_monFreq .GT. 0. _d 0 ) THEN |
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C Count iterations |
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totalJFNKtimeSteps = totalJFNKtimeSteps + 1 |
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totalNewtonIters = totalNewtonIters + newtonIter |
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totalKrylovIters = totalKrylovIters + totalKrylovItersLoc |
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C Record failure |
320 |
totalKrylovFails = totalKrylovFails + krylovFails |
321 |
IF ( newtonIter .EQ. SEAICEnewtonIterMax ) THEN |
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totalNewtonFails = totalNewtonFails + 1 |
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ENDIF |
324 |
ENDIF |
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C Decide whether it is time to dump and reset the counter |
326 |
writeNow = DIFFERENT_MULTIPLE(SEAICE_monFreq, |
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& myTime+deltaTClock, deltaTClock) |
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#ifdef ALLOW_CAL |
329 |
IF ( useCAL ) THEN |
330 |
CALL CAL_TIME2DUMP( |
331 |
I zeroRL, SEAICE_monFreq, deltaTClock, |
332 |
U writeNow, |
333 |
I myTime+deltaTclock, myIter+1, myThid ) |
334 |
ENDIF |
335 |
#endif |
336 |
IF ( writeNow ) THEN |
337 |
_BEGIN_MASTER( myThid ) |
338 |
WRITE(msgBuf,'(A)') |
339 |
&' // =======================================================' |
340 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
341 |
& SQUEEZE_RIGHT, myThid ) |
342 |
WRITE(msgBuf,'(A)') ' // Begin JFNK statistics' |
343 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
344 |
& SQUEEZE_RIGHT, myThid ) |
345 |
WRITE(msgBuf,'(A)') |
346 |
&' // =======================================================' |
347 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
348 |
& SQUEEZE_RIGHT, myThid ) |
349 |
WRITE(msgBuf,'(A,I10)') |
350 |
& ' %JFNK_MON: time step = ', myIter+1 |
351 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
352 |
& SQUEEZE_RIGHT, myThid ) |
353 |
WRITE(msgBuf,'(A,I10)') |
354 |
& ' %JFNK_MON: Nb. of time steps = ', totalJFNKtimeSteps |
355 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
356 |
& SQUEEZE_RIGHT, myThid ) |
357 |
WRITE(msgBuf,'(A,I10)') |
358 |
& ' %JFNK_MON: Nb. of Newton steps = ', totalNewtonIters |
359 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
360 |
& SQUEEZE_RIGHT, myThid ) |
361 |
WRITE(msgBuf,'(A,I10)') |
362 |
& ' %JFNK_MON: Nb. of Krylov steps = ', totalKrylovIters |
363 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
364 |
& SQUEEZE_RIGHT, myThid ) |
365 |
WRITE(msgBuf,'(A,I10)') |
366 |
& ' %JFNK_MON: Nb. of Newton failures = ', totalNewtonFails |
367 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
368 |
& SQUEEZE_RIGHT, myThid ) |
369 |
WRITE(msgBuf,'(A,I10)') |
370 |
& ' %JFNK_MON: Nb. of Krylov failures = ', totalKrylovFails |
371 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
372 |
& SQUEEZE_RIGHT, myThid ) |
373 |
WRITE(msgBuf,'(A)') |
374 |
&' // =======================================================' |
375 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
376 |
& SQUEEZE_RIGHT, myThid ) |
377 |
WRITE(msgBuf,'(A)') ' // End JFNK statistics' |
378 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
379 |
& SQUEEZE_RIGHT, myThid ) |
380 |
WRITE(msgBuf,'(A)') |
381 |
&' // =======================================================' |
382 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
383 |
& SQUEEZE_RIGHT, myThid ) |
384 |
_END_MASTER( myThid ) |
385 |
C reset and start again |
386 |
totalJFNKtimeSteps = 0 |
387 |
totalNewtonIters = 0 |
388 |
totalKrylovIters = 0 |
389 |
totalKrylovFails = 0 |
390 |
totalNewtonFails = 0 |
391 |
ENDIF |
392 |
|
393 |
C Print more debugging information |
394 |
IF ( debugLevel.GE.debLevA ) THEN |
395 |
IF ( newtonIter .EQ. SEAICEnewtonIterMax ) THEN |
396 |
_BEGIN_MASTER( myThid ) |
397 |
WRITE(msgBuf,'(A,I10)') |
398 |
& ' S/R SEAICE_JFNK: JFNK did not converge in timestep ', |
399 |
& myIter+1 |
400 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
401 |
& SQUEEZE_RIGHT, myThid ) |
402 |
_END_MASTER( myThid ) |
403 |
ENDIF |
404 |
IF ( krylovFails .GT. 0 ) THEN |
405 |
_BEGIN_MASTER( myThid ) |
406 |
WRITE(msgBuf,'(A,I4,A,I10)') |
407 |
& ' S/R SEAICE_JFNK: FGMRES did not converge ', |
408 |
& krylovFails, ' times in timestep ', myIter+1 |
409 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
410 |
& SQUEEZE_RIGHT, myThid ) |
411 |
_END_MASTER( myThid ) |
412 |
ENDIF |
413 |
_BEGIN_MASTER( myThid ) |
414 |
WRITE(msgBuf,'(A,I6,A,I10)') |
415 |
& ' S/R SEAICE_JFNK: Total number FGMRES iterations = ', |
416 |
& totalKrylovItersLoc, ' in timestep ', myIter+1 |
417 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
418 |
& SQUEEZE_RIGHT, myThid ) |
419 |
_END_MASTER( myThid ) |
420 |
ENDIF |
421 |
|
422 |
RETURN |
423 |
END |
424 |
|
425 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
426 |
CBOP |
427 |
C !ROUTINE: SEAICE_JFNK_UPDATE |
428 |
C !INTERFACE: |
429 |
|
430 |
SUBROUTINE SEAICE_JFNK_UPDATE( |
431 |
I duIce, dvIce, |
432 |
U uIce, vIce, JFNKresidual, |
433 |
O uIceRes, vIceRes, |
434 |
I newtonIter, myTime, myIter, myThid ) |
435 |
|
436 |
C !DESCRIPTION: \bv |
437 |
C *==========================================================* |
438 |
C | SUBROUTINE SEAICE_JFNK_UPDATE |
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C | o Update velocities with incremental solutions of FGMRES |
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C | o compute residual of updated solutions and do |
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C | o linesearch: |
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C | reduce update until residual is smaller than previous |
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C | one (input) |
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C *==========================================================* |
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C | written by Martin Losch, Jan 2013 |
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C *==========================================================* |
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C \ev |
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|
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C !USES: |
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IMPLICIT NONE |
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|
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C === Global variables === |
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "SEAICE_SIZE.h" |
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#include "SEAICE_PARAMS.h" |
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|
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C !INPUT/OUTPUT PARAMETERS: |
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C === Routine arguments === |
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C myTime :: Simulation time |
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C myIter :: Simulation timestep number |
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C myThid :: my Thread Id. number |
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C newtonIter :: current iterate of Newton iteration |
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_RL myTime |
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INTEGER myIter |
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INTEGER myThid |
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INTEGER newtonIter |
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C JFNKresidual :: Residual at the beginning of the FGMRES iteration, |
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C changes with newtonIter (updated) |
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_RL JFNKresidual |
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C du/vIce :: ice velocity increment to be added to u/vIce (input) |
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_RL duIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL dvIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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C u/vIce :: ice velocity increment to be added to u/vIce (updated) |
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_RL uIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL vIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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C u/vIceRes :: residual of sea-ice momentum equations (output) |
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_RL uIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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_RL vIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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|
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C !LOCAL VARIABLES: |
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C === Local variables === |
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C i,j,bi,bj :: loop indices |
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INTEGER i,j,bi,bj |
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INTEGER l |
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_RL resLoc, facLS |
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LOGICAL doLineSearch |
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C nVec :: size of the input vector(s) |
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C resTmp :: vector version of the residuals |
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INTEGER nVec |
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PARAMETER ( nVec = 2*sNx*sNy ) |
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_RL resTmp (nVec,1,nSx,nSy) |
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|
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CHARACTER*(MAX_LEN_MBUF) msgBuf |
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CEOP |
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|
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C Initialise some local variables |
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l = 0 |
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resLoc = JFNKresidual |
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facLS = 1. _d 0 |
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doLineSearch = .TRUE. |
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DO WHILE ( doLineSearch ) |
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C Create update |
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DO bj=myByLo(myThid),myByHi(myThid) |
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DO bi=myBxLo(myThid),myBxHi(myThid) |
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DO J=1-OLy,sNy+OLy |
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DO I=1-OLx,sNx+OLx |
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uIce(I,J,bi,bj) = uIce(I,J,bi,bj)+facLS*duIce(I,J,bi,bj) |
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vIce(I,J,bi,bj) = vIce(I,J,bi,bj)+facLS*dvIce(I,J,bi,bj) |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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C Compute current residual F(u), (includes re-computation of global |
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C variables DWATN, zeta, and eta, i.e. they are different after this) |
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CALL SEAICE_CALC_RESIDUAL( |
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I uIce, vIce, |
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O uIceRes, vIceRes, |
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I newtonIter, 0, myTime, myIter, myThid ) |
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C Important: Compute the norm of the residual using the same scalar |
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C product that SEAICE_FGMRES does |
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CALL SEAICE_MAP2VEC(nVec,uIceRes,vIceRes,resTmp,.TRUE.,myThid) |
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CALL SEAICE_SCALPROD(nVec,1,1,1,resTmp,resTmp,resLoc,myThid) |
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resLoc = SQRT(resLoc) |
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C Determine, if we need more iterations |
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doLineSearch = resLoc .GE. JFNKresidual |
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C Limit the maximum number of iterations arbitrarily to four |
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doLineSearch = doLineSearch .AND. l .LT. 4 |
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C For the first iteration du/vIce = 0 and there will be no |
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C improvement of the residual possible, so we do only the first |
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C iteration |
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IF ( newtonIter .EQ. 1 ) doLineSearch = .FALSE. |
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C Only start a linesearch after some Newton iterations |
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IF ( newtonIter .LE. SEAICE_JFNK_lsIter ) doLineSearch = .FALSE. |
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C Increment counter |
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l = l + 1 |
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C some output diagnostics |
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IF ( debugLevel.GE.debLevA .AND. doLineSearch ) THEN |
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_BEGIN_MASTER( myThid ) |
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WRITE(msgBuf,'(2A,2(1XI6),3E12.5)') |
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& ' S/R SEAICE_JFNK_UPDATE: Newton iter, LSiter, ', |
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& 'facLS, JFNKresidual, resLoc = ', |
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& newtonIter, l, facLS, JFNKresidual, resLoc |
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CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
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& SQUEEZE_RIGHT, myThid ) |
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_END_MASTER( myThid ) |
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ENDIF |
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C Get ready for the next iteration: after adding du/vIce in the first |
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C iteration, we substract 0.5*du/vIce from u/vIce in the next |
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C iterations, 0.25*du/vIce in the second, etc. |
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facLS = - 0.5 _d 0 * ABS(facLS) |
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ENDDO |
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C This is the new residual |
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JFNKresidual = resLoc |
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|
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#endif /* SEAICE_ALLOW_JFNK */ |
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|
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RETURN |
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END |