--- MITgcm/pkg/seaice/seaice_jfnk.F 2012/11/06 12:53:14 1.3 +++ MITgcm/pkg/seaice/seaice_jfnk.F 2013/05/30 14:07:19 1.23 @@ -1,8 +1,13 @@ -C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/pkg/seaice/seaice_jfnk.F,v 1.3 2012/11/06 12:53:14 mlosch Exp $ +C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/pkg/seaice/seaice_jfnk.F,v 1.23 2013/05/30 14:07:19 mlosch Exp $ C $Name: $ #include "SEAICE_OPTIONS.h" +C-- File seaice_jfnk.F: seaice jfnk dynamical solver S/R: +C-- Contents +C-- o SEAICE_JFNK +C-- o SEAICE_JFNK_UPDATE + CBOP C !ROUTINE: SEAICE_JFNK C !INTERFACE: @@ -10,7 +15,7 @@ C !DESCRIPTION: \bv C *==========================================================* -C | SUBROUTINE SEAICE_JFKF +C | SUBROUTINE SEAICE_JFNK C | o Ice dynamics using a Jacobian-free Newton-Krylov solver C | following J.-F. Lemieux et al. Improving the numerical C | convergence of viscous-plastic sea ice models with the @@ -48,78 +53,116 @@ INTEGER myIter INTEGER myThid -#if ( (defined SEAICE_CGRID) && \ - (defined SEAICE_ALLOW_JFNK) && \ - (defined SEAICE_ALLOW_DYNAMICS) ) +#ifdef SEAICE_ALLOW_JFNK +C !FUNCTIONS: + LOGICAL DIFFERENT_MULTIPLE + EXTERNAL DIFFERENT_MULTIPLE +C !LOCAL VARIABLES: +C === Local variables === C i,j,bi,bj :: loop indices INTEGER i,j,bi,bj C loop indices - INTEGER newtonIter, newtonIterFail - INTEGER krylovIter, krylovIterFail - INTEGER totalKrylovIter -C FGMRES flag that indicates what to do next + INTEGER newtonIter + INTEGER krylovIter, krylovFails + INTEGER totalKrylovItersLoc, totalNewtonItersLoc +C FGMRES flag that determines amount of output messages of fgmres + INTEGER iOutFGMRES +C FGMRES flag that indicates what fgmres wants us to do next INTEGER iCode - _RL JFNKresidual, JFNKresidualTile(nSx,nSy) + _RL JFNKresidual _RL JFNKresidualKm1 C parameters to compute convergence criterion - _RL phi_e, alp_e, JFNKgamma_lin + _RL JFNKgamma_lin _RL FGMRESeps _RL JFNKtol -C +C Adams-Bashforth extrapolation factors + _RL abFac, abAlpha +C _RL recip_deltaT LOGICAL JFNKconverged, krylovConverged + LOGICAL writeNow CHARACTER*(MAX_LEN_MBUF) msgBuf -C + C u/vIceRes :: residual of sea-ice momentum equations _RL uIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RL vIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) +C extra time level required for Adams-Bashforth-2 time stepping + _RL duIcNm1(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) + _RL dvIcNm1(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) C du/vIce :: ice velocity increment to be added to u/vIce _RL duIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RL dvIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) -C precomputed (= constant per Newton iteration) versions of +C precomputed (= constant per Newton iteration) versions of C zeta, eta, and DWATN, press _RL zetaPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RL etaPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) + _RL etaZPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RL dwatPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) - _RL pressPre(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) CEOP C Initialise - newtonIter = 0 - newtonIterFail = 0 - krylovIterFail = 0 - totalKrylovIter = 0 - JFNKconverged = .FALSE. - JFNKtol = 0. _d 0 - JFNKresidual = 0. _d 0 - JFNKresidualKm1 = 0. _d 0 - FGMRESeps = 0. _d 0 - recip_deltaT = 1. _d 0 / SEAICE_deltaTdyn -C + newtonIter = 0 + krylovFails = 0 + totalKrylovItersLoc = 0 + JFNKconverged = .FALSE. + JFNKtol = 0. _d 0 + JFNKresidual = 0. _d 0 + JFNKresidualKm1 = 0. _d 0 + FGMRESeps = 0. _d 0 + recip_deltaT = 1. _d 0 / SEAICE_deltaTdyn + + iOutFGMRES=0 +C with iOutFgmres=1, seaice_fgmres prints the residual at each iteration + IF ( debugLevel.GE.debLevC .AND. + & DIFFERENT_MULTIPLE( SEAICE_monFreq, myTime, deltaTClock ) ) + & iOutFGMRES=1 + +C Adams-Bashforth extrapolation factors + abFac = 0. _d 0 + IF ( SEAICEuseAB2 ) THEN + IF ( myIter.EQ.nIter0 .AND. SEAICEmomStartAB.EQ.0 ) THEN + abFac = 0. _d 0 + ELSE + abFac = 0.5 _d 0 + SEAICE_abEps + ENDIF + ENDIF + abAlpha = 1. _d 0 + abFac + DO bj=myByLo(myThid),myByHi(myThid) DO bi=myBxLo(myThid),myBxHi(myThid) - DO J=1-Oly,sNy+Oly - DO I=1-Olx,sNx+Olx + DO J=1-OLy,sNy+OLy + DO I=1-OLx,sNx+OLx uIceRes(I,J,bi,bj) = 0. _d 0 vIceRes(I,J,bi,bj) = 0. _d 0 duIce (I,J,bi,bj) = 0. _d 0 dvIce (I,J,bi,bj) = 0. _d 0 + ENDDO + ENDDO +C cycle ice velocities + DO J=1-OLy,sNy+OLy + DO I=1-OLx,sNx+OLx + duIcNm1(I,J,bi,bj) = uIce(I,J,bi,bj) * abAlpha + & + ( uIce(I,J,bi,bj) - uIceNm1(I,J,bi,bj) ) * abFac + dvIcNm1(I,J,bi,bj) = vIce(I,J,bi,bj) * abAlpha + & + ( vIce(I,J,bi,bj) - vIceNm1(I,J,bi,bj) ) * abFac uIceNm1(I,J,bi,bj) = uIce(I,J,bi,bj) vIceNm1(I,J,bi,bj) = vIce(I,J,bi,bj) ENDDO ENDDO + IF ( .NOT.SEAICEuseIMEX ) THEN C Compute things that do no change during the Newton iteration: -C sea-surface tilt and wind stress: -C FORCEX/Y0 - mass*(u/vIceNm1)/deltaT - DO J=1-Oly,sNy+Oly - DO I=1-Olx,sNx+Olx +C sea-surface tilt and wind stress: +C FORCEX/Y0 - mass*(abA*u/vIceNm1+abB*(u/vIceNm1-u/vIceNm2))/deltaT + DO J=1-OLy,sNy+OLy + DO I=1-OLx,sNx+OLx FORCEX(I,J,bi,bj) = FORCEX0(I,J,bi,bj) - & + seaiceMassU(I,J,bi,bj)*uIceNm1(I,J,bi,bj)*recip_deltaT + & + seaiceMassU(I,J,bi,bj)*duIcNm1(I,J,bi,bj)*recip_deltaT FORCEY(I,J,bi,bj) = FORCEY0(I,J,bi,bj) - & + seaiceMassV(I,J,bi,bj)*vIceNm1(I,J,bi,bj)*recip_deltaT + & + seaiceMassV(I,J,bi,bj)*dvIcNm1(I,J,bi,bj)*recip_deltaT ENDDO ENDDO + ENDIF ENDDO ENDDO C Start nonlinear Newton iteration: outer loop iteration @@ -128,64 +171,38 @@ newtonIter = newtonIter + 1 C Compute initial residual F(u), (includes computation of global C variables DWATN, zeta, and eta) - CALL SEAICE_CALC_RESIDUAL( - I uIce, vIce, - O uIceRes, vIceRes, - I newtonIter, 0, myTime, myIter, myThid ) - CALL EXCH_UV_XY_RL( uIceRes, vIceRes,.TRUE.,myThid) + IF ( newtonIter .EQ. 1 ) CALL SEAICE_JFNK_UPDATE( + I duIce, dvIce, + U uIce, vIce, JFNKresidual, + O uIceRes, vIceRes, + I newtonIter, myTime, myIter, myThid ) C local copies of precomputed coefficients that are to stay C constant for the preconditioner DO bj=myByLo(myThid),myByHi(myThid) DO bi=myBxLo(myThid),myBxHi(myThid) - DO j=1-Oly,sNy+Oly - DO i=1-Olx,sNx+Olx - zetaPre(I,J,bi,bj) = zeta(I,J,bi,bj) - etaPre(I,J,bi,bj) = eta(I,J,bi,bj) - dwatPre(I,J,bi,bj) = DWATN(I,J,bi,bj) - pressPre(I,J,bi,bj) = press(I,J,bi,bj) + DO j=1-OLy,sNy+OLy + DO i=1-OLx,sNx+OLx + zetaPre(I,J,bi,bj) = zeta(I,J,bi,bj) + etaPre(I,J,bi,bj) = eta(I,J,bi,bj) + etaZPre(I,J,bi,bj) = etaZ(I,J,bi,bj) + dwatPre(I,J,bi,bj) = DWATN(I,J,bi,bj) ENDDO ENDDO ENDDO ENDDO -C - DO bj=myByLo(myThid),myByHi(myThid) - DO bi=myBxLo(myThid),myBxHi(myThid) - JFNKresidualTile(bi,bj) = 0. _d 0 - DO J=1,sNy - DO I=1,sNx -#ifdef CG2D_SINGLECPU_SUM - JFNKlocalBuf(I,J,bi,bj) = -#else - JFNKresidualTile(bi,bj) = JFNKresidualTile(bi,bj) + -#endif - & uIceRes(I,J,bi,bj)*uIceRes(I,J,bi,bj) + - & vIceRes(I,J,bi,bj)*vIceRes(I,J,bi,bj) - ENDDO - ENDDO - ENDDO - ENDDO - JFNKresidual = 0. _d 0 -#ifdef CG2D_SINGLECPU_SUM - CALL GLOBAL_SUM_SINGLECPU_RL( - & JFNKlocalBuf,JFNKresidual, 0, 0, myThid) -#else - CALL GLOBAL_SUM_TILE_RL( JFNKresidualTile,JFNKresidual,myThid ) -#endif - JFNKresidual = SQRT(JFNKresidual) C compute convergence criterion for linear preconditioned FGMRES JFNKgamma_lin = JFNKgamma_lin_max - IF ( newtonIter.GT.1.AND.newtonIter.LE.100 + IF ( newtonIter.GT.1.AND.newtonIter.LE.SEAICE_JFNK_tolIter & .AND.JFNKresidual.LT.JFNKres_t ) THEN -C Eisenstat, 1996, equ.(2.6) - phi_e = 1. _d 0 - alp_e = 1. _d 0 - JFNKgamma_lin = phi_e*( JFNKresidual/JFNKresidualKm1 )**alp_e +C Eisenstat and Walker (1996), eq.(2.6) + JFNKgamma_lin = SEAICE_JFNKphi + & *( JFNKresidual/JFNKresidualKm1 )**SEAICE_JFNKalpha JFNKgamma_lin = min(JFNKgamma_lin_max, JFNKgamma_lin) JFNKgamma_lin = max(JFNKgamma_lin_min, JFNKgamma_lin) ENDIF C save the residual for the next iteration JFNKresidualKm1 = JFNKresidual -C + C The Krylov iteration using FGMRES, the preconditioner is LSOR C for now. The code is adapted from SEAICE_LSR, but heavily stripped C down. @@ -193,111 +210,350 @@ C in that routine krylovIter = 0 iCode = 0 - IF ( debugLevel.GE.debLevA ) THEN - WRITE(msgBuf,'(2A,2(1XI6),2E12.5)') - & ' S/R SEAICE_JFNK: newtonIter,', - & ' total newtonIter, JFNKgamma_lin, initial norm = ', - & newtonIter,SEAICEnewtonIterMax*(myIter-nIter0)+newtonIter, - & JFNKgamma_lin, JFNKresidual - CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, - & SQUEEZE_RIGHT, myThid ) - ENDIF -C + JFNKconverged = JFNKresidual.LT.JFNKtol -C + C do Krylov loop only if convergence is not reached -C + IF ( .NOT.JFNKconverged ) THEN -C + C start Krylov iteration (FGMRES) -C + krylovConverged = .FALSE. FGMRESeps = JFNKgamma_lin * JFNKresidual - DO WHILE ( .NOT.krylovConverged ) + DO WHILE ( .NOT.krylovConverged ) C solution vector sol = du/vIce C residual vector (rhs) Fu = u/vIceRes -C output work vectors wk1, -> input work vector wk2 -C +C output work vectors wk1, -> input work vector wk2 + CALL SEAICE_FGMRES_DRIVER( - I uIceRes, vIceRes, + I uIceRes, vIceRes, U duIce, dvIce, iCode, - I FGMRESeps, + I FGMRESeps, iOutFGMRES, I newtonIter, krylovIter, myTime, myIter, myThid ) C FGMRES returns iCode either asking for an new preconditioned vector C or product of matrix (Jacobian) times vector. For iCode = 0, terminate C iteration IF (iCode.EQ.1) THEN C Call preconditioner - CALL SEAICE_PRECONDITIONER( - U duIce, dvIce, - I zetaPre, etaPre, dwatPre, pressPre, + IF ( SOLV_MAX_ITERS .GT. 0 ) + & CALL SEAICE_PRECONDITIONER( + U duIce, dvIce, + I zetaPre, etaPre, etaZpre, dwatPre, I newtonIter, krylovIter, myTime, myIter, myThid ) ELSEIF (iCode.GE.2) THEN C Compute Jacobian times vector CALL SEAICE_JACVEC( I uIce, vIce, uIceRes, vIceRes, - U duIce, dvIce, + U duIce, dvIce, I newtonIter, krylovIter, myTime, myIter, myThid ) ENDIF krylovConverged = iCode.EQ.0 C End of Krylov iterate ENDDO - totalKrylovIter = totalKrylovIter + krylovIter + totalKrylovItersLoc = totalKrylovItersLoc + krylovIter C some output diagnostics IF ( debugLevel.GE.debLevA ) THEN + _BEGIN_MASTER( myThid ) + totalNewtonItersLoc = + & SEAICEnewtonIterMax*(myIter-nIter0)+newtonIter + WRITE(msgBuf,'(2A,2(1XI6),2E12.5)') + & ' S/R SEAICE_JFNK: Newton iterate / total, ', + & 'JFNKgamma_lin, initial norm = ', + & newtonIter, totalNewtonItersLoc, + & JFNKgamma_lin,JFNKresidual + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) WRITE(msgBuf,'(3(A,I6))') - & ' S/R SEAICE_JFNK: Newton iterate / total = ', newtonIter, - & ' / ', SEAICEnewtonIterMax*(myIter-nIter0)+newtonIter, + & ' S/R SEAICE_JFNK: Newton iterate / total = ',newtonIter, + & ' / ', totalNewtonItersLoc, & ', Nb. of FGMRES iterations = ', krylovIter CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, & SQUEEZE_RIGHT, myThid ) + _END_MASTER( myThid ) ENDIF IF ( krylovIter.EQ.SEAICEkrylovIterMax ) THEN - krylovIterFail = krylovIterFail + 1 + krylovFails = krylovFails + 1 + ENDIF +C Set the stopping criterion for the Newton iteration and the +C criterion for the transition from accurate to approximate FGMRES + IF ( newtonIter .EQ. 1 ) THEN + JFNKtol=JFNKgamma_nonlin*JFNKresidual + IF ( JFNKres_tFac .NE. UNSET_RL ) + & JFNKres_t = JFNKresidual * JFNKres_tFac ENDIF C Update linear solution vector and return to Newton iteration +C Do a linesearch if necessary, and compute a new residual. +C Note that it should be possible to do the following operations +C at the beginning of the Newton iteration, thereby saving us from +C the extra call of seaice_jfnk_update, but unfortunately that +C changes the results, so we leave the stuff here for now. + CALL SEAICE_JFNK_UPDATE( + I duIce, dvIce, + U uIce, vIce, JFNKresidual, + O uIceRes, vIceRes, + I newtonIter, myTime, myIter, myThid ) +C reset du/vIce here instead of setting sol = 0 in seaice_fgmres_driver DO bj=myByLo(myThid),myByHi(myThid) DO bi=myBxLo(myThid),myBxHi(myThid) - DO J=1-Oly,sNy+Oly - DO I=1-Olx,sNx+Olx - uIce(I,J,bi,bj) = uIce(I,J,bi,bj)+duIce(I,J,bi,bj) - vIce(I,J,bi,bj) = vIce(I,J,bi,bj)+dvIce(I,J,bi,bj) + DO J=1-OLy,sNy+OLy + DO I=1-OLx,sNx+OLx + duIce(I,J,bi,bj)= 0. _d 0 + dvIce(I,J,bi,bj)= 0. _d 0 ENDDO ENDDO ENDDO ENDDO -C Set the stopping criterion for the Newton iteration - IF ( newtonIter .EQ. 1 ) JFNKtol=JFNKgamma_nonlin*JFNKresidual ENDIF C end of Newton iterate ENDDO -C some output diagnostics - IF ( debugLevel.GE.debLevA ) THEN + +C-- Output diagnostics + + IF ( SEAICE_monFreq .GT. 0. _d 0 ) THEN +C Count iterations + totalJFNKtimeSteps = totalJFNKtimeSteps + 1 + totalNewtonIters = totalNewtonIters + newtonIter + totalKrylovIters = totalKrylovIters + totalKrylovItersLoc C Record failure + totalKrylovFails = totalKrylovFails + krylovFails IF ( newtonIter .EQ. SEAICEnewtonIterMax ) THEN - newtonIterFail = newtonIterFail + 1 - WRITE(msgBuf,'(A,I10)') + totalNewtonFails = totalNewtonFails + 1 + ENDIF + ENDIF +C Decide whether it is time to dump and reset the counter + writeNow = DIFFERENT_MULTIPLE(SEAICE_monFreq, + & myTime+deltaTClock, deltaTClock) +#ifdef ALLOW_CAL + IF ( useCAL ) THEN + CALL CAL_TIME2DUMP( + I zeroRL, SEAICE_monFreq, deltaTClock, + U writeNow, + I myTime+deltaTclock, myIter+1, myThid ) + ENDIF +#endif + IF ( writeNow ) THEN + _BEGIN_MASTER( myThid ) + WRITE(msgBuf,'(A)') + &' // =======================================================' + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A)') ' // Begin JFNK statistics' + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A)') + &' // =======================================================' + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A,I10)') + & ' %JFNK_MON: time step = ', myIter+1 + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A,I10)') + & ' %JFNK_MON: Nb. of time steps = ', totalJFNKtimeSteps + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A,I10)') + & ' %JFNK_MON: Nb. of Newton steps = ', totalNewtonIters + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A,I10)') + & ' %JFNK_MON: Nb. of Krylov steps = ', totalKrylovIters + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A,I10)') + & ' %JFNK_MON: Nb. of Newton failures = ', totalNewtonFails + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A,I10)') + & ' %JFNK_MON: Nb. of Krylov failures = ', totalKrylovFails + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A)') + &' // =======================================================' + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A)') ' // End JFNK statistics' + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + WRITE(msgBuf,'(A)') + &' // =======================================================' + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + _END_MASTER( myThid ) +C reset and start again + totalJFNKtimeSteps = 0 + totalNewtonIters = 0 + totalKrylovIters = 0 + totalKrylovFails = 0 + totalNewtonFails = 0 + ENDIF + +C Print more debugging information + IF ( debugLevel.GE.debLevA ) THEN + IF ( newtonIter .EQ. SEAICEnewtonIterMax ) THEN + _BEGIN_MASTER( myThid ) + WRITE(msgBuf,'(A,I10)') & ' S/R SEAICE_JFNK: JFNK did not converge in timestep ', - & myIter + & myIter+1 CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, & SQUEEZE_RIGHT, myThid ) + _END_MASTER( myThid ) ENDIF - IF ( krylovIterFail .GT. 0 ) THEN - WRITE(msgBuf,'(A,I4,A,I10)') + IF ( krylovFails .GT. 0 ) THEN + _BEGIN_MASTER( myThid ) + WRITE(msgBuf,'(A,I4,A,I10)') & ' S/R SEAICE_JFNK: FGMRES did not converge ', - & krylovIterFail, ' times in timestep ', myIter + & krylovFails, ' times in timestep ', myIter+1 CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, & SQUEEZE_RIGHT, myThid ) + _END_MASTER( myThid ) ENDIF - WRITE(msgBuf,'(A,I6)') + _BEGIN_MASTER( myThid ) + WRITE(msgBuf,'(A,I6,A,I10)') & ' S/R SEAICE_JFNK: Total number FGMRES iterations = ', - & totalKrylovIter + & totalKrylovItersLoc, ' in timestep ', myIter+1 + CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, + & SQUEEZE_RIGHT, myThid ) + _END_MASTER( myThid ) + ENDIF + + RETURN + END + +C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| +CBOP +C !ROUTINE: SEAICE_JFNK_UPDATE +C !INTERFACE: + + SUBROUTINE SEAICE_JFNK_UPDATE( + I duIce, dvIce, + U uIce, vIce, JFNKresidual, + O uIceRes, vIceRes, + I newtonIter, myTime, myIter, myThid ) + +C !DESCRIPTION: \bv +C *==========================================================* +C | SUBROUTINE SEAICE_JFNK_UPDATE +C | o Update velocities with incremental solutions of FGMRES +C | o compute residual of updated solutions and do +C | o linesearch: +C | reduce update until residual is smaller than previous +C | one (input) +C *==========================================================* +C | written by Martin Losch, Jan 2013 +C *==========================================================* +C \ev + +C !USES: + IMPLICIT NONE + +C === Global variables === +#include "SIZE.h" +#include "EEPARAMS.h" +#include "PARAMS.h" +#include "SEAICE_SIZE.h" +#include "SEAICE_PARAMS.h" + +C !INPUT/OUTPUT PARAMETERS: +C === Routine arguments === +C myTime :: Simulation time +C myIter :: Simulation timestep number +C myThid :: my Thread Id. number +C newtonIter :: current iterate of Newton iteration + _RL myTime + INTEGER myIter + INTEGER myThid + INTEGER newtonIter +C JFNKresidual :: Residual at the beginning of the FGMRES iteration, +C changes with newtonIter (updated) + _RL JFNKresidual +C du/vIce :: ice velocity increment to be added to u/vIce (input) + _RL duIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) + _RL dvIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) +C u/vIce :: ice velocity increment to be added to u/vIce (updated) + _RL uIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) + _RL vIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) +C u/vIceRes :: residual of sea-ice momentum equations (output) + _RL uIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) + _RL vIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) + +C !LOCAL VARIABLES: +C === Local variables === +C i,j,bi,bj :: loop indices + INTEGER i,j,bi,bj + INTEGER l + _RL resLoc, facLS + LOGICAL doLineSearch +C nVec :: size of the input vector(s) +C resTmp :: vector version of the residuals + INTEGER nVec + PARAMETER ( nVec = 2*sNx*sNy ) + _RL resTmp (nVec,1,nSx,nSy) + + CHARACTER*(MAX_LEN_MBUF) msgBuf +CEOP + +C Initialise some local variables + l = 0 + resLoc = JFNKresidual + facLS = 1. _d 0 + doLineSearch = .TRUE. + DO WHILE ( doLineSearch ) +C Create update + DO bj=myByLo(myThid),myByHi(myThid) + DO bi=myBxLo(myThid),myBxHi(myThid) + DO J=1-OLy,sNy+OLy + DO I=1-OLx,sNx+OLx + uIce(I,J,bi,bj) = uIce(I,J,bi,bj)+facLS*duIce(I,J,bi,bj) + vIce(I,J,bi,bj) = vIce(I,J,bi,bj)+facLS*dvIce(I,J,bi,bj) + ENDDO + ENDDO + ENDDO + ENDDO +C Compute current residual F(u), (includes re-computation of global +C variables DWATN, zeta, and eta, i.e. they are different after this) + CALL SEAICE_CALC_RESIDUAL( + I uIce, vIce, + O uIceRes, vIceRes, + I newtonIter, 0, myTime, myIter, myThid ) +C Important: Compute the norm of the residual using the same scalar +C product that SEAICE_FGMRES does + CALL SEAICE_MAP2VEC(nVec,uIceRes,vIceRes,resTmp,.TRUE.,myThid) + CALL SEAICE_SCALPROD(nVec,1,1,1,resTmp,resTmp,resLoc,myThid) + resLoc = SQRT(resLoc) +C Determine, if we need more iterations + doLineSearch = resLoc .GE. JFNKresidual +C Limit the maximum number of iterations arbitrarily to four + doLineSearch = doLineSearch .AND. l .LT. 4 +C For the first iteration du/vIce = 0 and there will be no +C improvement of the residual possible, so we do only the first +C iteration + IF ( newtonIter .EQ. 1 ) doLineSearch = .FALSE. +C Only start a linesearch after some Newton iterations + IF ( newtonIter .LE. SEAICE_JFNK_lsIter ) doLineSearch = .FALSE. +C Increment counter + l = l + 1 +C some output diagnostics + IF ( debugLevel.GE.debLevA .AND. doLineSearch ) THEN + _BEGIN_MASTER( myThid ) + WRITE(msgBuf,'(2A,2(1XI6),3E12.5)') + & ' S/R SEAICE_JFNK_UPDATE: Newton iter, LSiter, ', + & 'facLS, JFNKresidual, resLoc = ', + & newtonIter, l, facLS, JFNKresidual, resLoc CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, & SQUEEZE_RIGHT, myThid ) - - ENDIF + _END_MASTER( myThid ) + ENDIF +C Get ready for the next iteration: after adding du/vIce in the first +C iteration, we substract 0.5*du/vIce from u/vIce in the next +C iterations, 0.25*du/vIce in the second, etc. + facLS = - 0.5 _d 0 * ABS(facLS) + ENDDO +C This is the new residual + JFNKresidual = resLoc -#endif /* SEAICE_ALLOW_DYNAMICS and SEAICE_CGRID and SEAICE_ALLOW_JFNK */ +#endif /* SEAICE_ALLOW_JFNK */ RETURN END