Actual source code: ex30.c

petsc-3.3-p7 2013-05-11
  1: static const char help[] = "Steady-state 2D subduction flow, pressure and temperature solver.\n\
  2:        The flow is driven by the subducting slab.\n\
  3: ---------------------------------ex30 help---------------------------------\n\
  4:   -OPTION <DEFAULT> = (UNITS) DESCRIPTION.\n\n\
  5:   -width <320> = (km) width of domain.\n\
  6:   -depth <300> = (km) depth of domain.\n\
  7:   -slab_dip <45> = (degrees) dip angle of the slab (determines the grid aspect ratio).\n\
  8:   -lid_depth <35> = (km) depth of the static conductive lid.\n\
  9:   -fault_depth <35> = (km) depth of slab-wedge mechanical coupling\n\
 10:      ( fault dept >= lid depth ).\n\
 11: \n\
 12:   -ni <82> = grid cells in x-direction. (nj adjusts to accommodate\n\
 13:       the slab dip & depth). DO NOT USE -da_grid_x option!!!\n\
 14:   -ivisc <3> = rheology option.\n\
 15:       0 --- constant viscosity.\n\
 16:       1 --- olivine diffusion creep rheology (T&P-dependent, newtonian).\n\
 17:       2 --- olivine dislocation creep rheology (T&P-dependent, non-newtonian).\n\
 18:       3 --- Full mantle rheology, combination of 1 & 2.\n\
 19: \n\
 20:   -slab_velocity <5> = (cm/year) convergence rate of slab into subduction zone.\n\
 21:   -slab_age <50> = (million yrs) age of slab for thermal profile boundary condition.\n\
 22:   -lid_age <50> = (million yrs) age of lid for thermal profile boundary condition.\n\
 23: \n\
 24:   FOR OTHER PARAMETER OPTIONS AND THEIR DEFAULT VALUES, see SetParams() in ex30.c.\n\
 25: ---------------------------------ex30 help---------------------------------\n";


 28: /*F-----------------------------------------------------------------------

This PETSc 2.2.0 example by Richard F. Katz
http://www.ldeo.columbia.edu/~katz/

The problem is modeled by the partial differential equation system

\begin{eqnarray}
-\nabla P + \nabla \cdot [\eta (\nabla v + \nabla v^T)] & = & 0 \\
\nabla \cdot v & = & 0 \\
dT/dt + \nabla \cdot (vT) - 1/Pe \triangle^2(T) & = & 0 \\
\end{eqnarray}

\begin{eqnarray}
\eta(T,Eps\_dot) & = & \hbox{constant } \hbox{if ivisc} ==0 \\
& = & \hbox{diffusion creep (T,P-dependent) } \hbox{if ivisc} ==1 \\
& = & \hbox{dislocation creep (T,P,v-dependent)} \hbox{if ivisc} ==2 \\
& = & \hbox{mantle viscosity (difn and disl) } \hbox{if ivisc} ==3
\end{eqnarray}

which is uniformly discretized on a staggered mesh:
-------$w_{ij}$------
$u_{i-1j}$ $P,T_{ij}$ $u_{ij}$
------$w_{ij-1}$-----

 53:   ------------------------------------------------------------------------F*/

 55: #include <petscsnes.h>
 56: #include <petscdmda.h>

 58: #define VISC_CONST   0
 59: #define VISC_DIFN    1
 60: #define VISC_DISL    2
 61: #define VISC_FULL    3
 62: #define CELL_CENTER  0
 63: #define CELL_CORNER  1
 64: #define BC_ANALYTIC  0
 65: #define BC_NOSTRESS  1
 66: #define BC_EXPERMNT  2
 67: #define ADVECT_FV    0
 68: #define ADVECT_FROMM 1
 69: #define PLATE_SLAB   0
 70: #define PLATE_LID    1
 71: #define EPS_ZERO     0.00000001

 73: typedef struct { /* holds the variables to be solved for */
 74:   PetscScalar u,w,p,T;
 75: } Field;

 77: typedef struct { /* parameters needed to compute viscosity */
 78:   PetscReal    A,n,Estar,Vstar;
 79: } ViscParam;

 81: typedef struct { /* physical and miscelaneous parameters */
 82:   PetscReal    width, depth, scaled_width, scaled_depth, peclet, potentialT;
 83:   PetscReal    slab_dip, slab_age, slab_velocity, kappa, z_scale;
 84:   PetscReal    c, d, sb, cb, skt, visc_cutoff, lid_age, eta0, continuation;
 85:   PetscReal    L, V, lid_depth, fault_depth;
 86:   ViscParam    diffusion, dislocation;
 87:   PetscInt     ivisc, adv_scheme, ibound, output_ivisc;
 88:   PetscBool    quiet, param_test, output_to_file, pv_analytic;
 89:   PetscBool    interrupted, stop_solve, toggle_kspmon, kspmon;
 90:   char         filename[PETSC_MAX_PATH_LEN];
 91: } Parameter;

 93: typedef struct { /* grid parameters */
 94:   DMDABoundaryType bx,by;
 95:   DMDAStencilType  stencil;
 96:   PetscInt       corner,ni,nj,jlid,jfault,inose;
 97:   PetscInt       dof,stencil_width,mglevels;
 98:   PetscReal      dx,dz;
 99: } GridInfo;

101: typedef struct { /* application context */
102:   Vec          x,Xguess;
103:   Parameter    *param;
104:   GridInfo     *grid;
105: } AppCtx;

107: /* Callback functions (static interface) */
108: extern PetscErrorCode FormFunctionLocal(DMDALocalInfo*,Field**,Field**,void*);

110: /* Main routines */
111: extern PetscErrorCode SetParams(Parameter*, GridInfo *);
112: extern PetscErrorCode ReportParams(Parameter *, GridInfo *);
113: extern PetscErrorCode Initialize(DM);
114: extern PetscErrorCode UpdateSolution(SNES,AppCtx*, PetscInt*);
115: extern PetscErrorCode DoOutput(SNES,PetscInt);

117: /* Post-processing & misc */
118: extern PetscErrorCode ViscosityField(DM,Vec,Vec);
119: extern PetscErrorCode StressField(DM);
120: extern PetscErrorCode SNESConverged_Interactive(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
121: extern PetscErrorCode InteractiveHandler(int, void *);
122: extern PetscBool  OptionsHasName(const char pre[],const char name[]);

124: /*-----------------------------------------------------------------------*/
127: int main(int argc,char **argv)
128: /*-----------------------------------------------------------------------*/
129: {
130:   SNES           snes;
131:   AppCtx         *user;               /* user-defined work context */
132:   Parameter      param;
133:   GridInfo       grid;
134:   PetscInt       nits;
136:   MPI_Comm       comm;
137:   DM             da;

139:   PetscInitialize(&argc,&argv,(char *)0,help);
140:   PetscOptionsSetValue("-file","ex30_output");
141:   PetscOptionsSetValue("-snes_monitor_short",PETSC_NULL);
142:   PetscOptionsSetValue("-snes_max_it","20");
143:   PetscOptionsSetValue("-ksp_max_it","1500");
144:   PetscOptionsSetValue("-ksp_gmres_restart","300");
145:   PetscOptionsInsert(&argc,&argv,PETSC_NULL);

147:   comm = PETSC_COMM_WORLD;

149:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
150:      Set up the problem parameters.
151:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
152:   SetParams(&param,&grid);
153:   ReportParams(&param,&grid);

155:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
156:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
157:   SNESCreate(comm,&snes);
158:   DMDACreate2d(comm,grid.bx,grid.by,grid.stencil,grid.ni,grid.nj,PETSC_DECIDE,PETSC_DECIDE,grid.dof,grid.stencil_width,0,0,&da);
159:   SNESSetDM(snes,da);
160:   DMDASetFieldName(da,0,"x-velocity");
161:   DMDASetFieldName(da,1,"y-velocity");
162:   DMDASetFieldName(da,2,"pressure");
163:   DMDASetFieldName(da,3,"temperature");


166:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
167:      Create user context, set problem data, create vector data structures.
168:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
169:   PetscMalloc(sizeof(AppCtx),&user);
170:   user->param   = &param;
171:   user->grid    = &grid;
172:   DMSetApplicationContext(da,user);
173:   DMCreateGlobalVector(da,&(user->Xguess));


176:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
177:      Set up the SNES solver with callback functions.
178:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
179:   DMDASetLocalFunction(da,(DMDALocalFunction1)FormFunctionLocal);
180:   SNESSetFromOptions(snes);


183:   SNESSetConvergenceTest(snes,SNESConverged_Interactive,(void*)user,PETSC_NULL);
184:   PetscPushSignalHandler(InteractiveHandler,(void*)user);
185: 
186:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
187:      Initialize and solve the nonlinear system
188:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
189:   Initialize(da);
190:   UpdateSolution(snes,user,&nits);
191: 
192:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
193:      Output variables.
194:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
195:   DoOutput(snes,nits);
196: 
197:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
198:      Free work space. 
199:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
200:   VecDestroy(&user->Xguess);
201:   VecDestroy(&user->x);
202:   PetscFree(user);
203:   SNESDestroy(&snes);
204:   DMDestroy(&da);
205:   PetscPopSignalHandler();
206:   PetscFinalize();
207:   return 0;
208: }

210: /*=====================================================================
211:   PETSc INTERACTION FUNCTIONS (initialize & call SNESSolve)
212:   =====================================================================*/

214: /*---------------------------------------------------------------------*/
217: /*  manages solve: adaptive continuation method  */
218: PetscErrorCode UpdateSolution(SNES snes, AppCtx *user, PetscInt *nits)
219: {
220:   KSP                 ksp;
221:   PC                  pc;
222:   SNESConvergedReason reason;
223:   Parameter           *param = user->param;
224:   PetscReal           cont_incr=0.3;
225:   PetscInt            its;
226:   PetscErrorCode      ierr;
227:   PetscBool           q = PETSC_FALSE;
228:   DM                  dm;

231:   SNESGetDM(snes,&dm);
232:   DMCreateGlobalVector(dm,&user->x);
233:   SNESGetKSP(snes,&ksp);
234:   KSPGetPC(ksp, &pc);
235:   KSPSetComputeSingularValues(ksp, PETSC_TRUE);

237:   *nits=0;

239:   /* Isoviscous solve */
240:   if (param->ivisc == VISC_CONST && !param->stop_solve) {
241:     param->ivisc = VISC_CONST;
242:     SNESSolve(snes,0,user->x);
243:     SNESGetConvergedReason(snes,&reason);
244:     SNESGetIterationNumber(snes,&its);
245:     *nits +=its;
246:     VecCopy(user->x,user->Xguess);
247:     if (param->stop_solve) goto done;
248:   }

250:   /* Olivine diffusion creep */
251:   if (param->ivisc >= VISC_DIFN && !param->stop_solve) {
252:     if (!q) PetscPrintf(PETSC_COMM_WORLD,"Computing Variable Viscosity Solution\n");

254:     /* continuation method on viscosity cutoff */
255:     for (param->continuation=0.0; ; param->continuation+=cont_incr) {
256:       if (!q) PetscPrintf(PETSC_COMM_WORLD," Continuation parameter = %G\n", param->continuation);

258:       /* solve the non-linear system */
259:       VecCopy(user->Xguess,user->x);
260:       SNESSolve(snes,0,user->x);
261:       SNESGetConvergedReason(snes,&reason);
262:       SNESGetIterationNumber(snes,&its);
263:       *nits += its;
264:       if (!q) PetscPrintf(PETSC_COMM_WORLD," SNES iterations: %D, Cumulative: %D\n", its, *nits);
265:       if (param->stop_solve) goto done;

267:       if (reason<0) {
268:         /* NOT converged */
269:         cont_incr = -fabs(cont_incr)/2.0;
270:         if (fabs(cont_incr)<0.01) goto done;

272:       } else {
273:         /* converged */
274:         VecCopy(user->x,user->Xguess);
275:         if (param->continuation >= 1.0) goto done;
276:         if (its<=3) {
277:           cont_incr = 0.30001;
278:         } else if (its<=8) {
279:           cont_incr = 0.15001;
280:         } else {
281:           cont_incr = 0.10001;
282:         }
283:         if (param->continuation+cont_incr > 1.0) {
284:           cont_incr = 1.0 - param->continuation;
285:         }
286:       } /* endif reason<0 */
287:     }
288:   }
289:   done:
290:   if (param->stop_solve && !q) PetscPrintf(PETSC_COMM_WORLD,"USER SIGNAL: stopping solve.\n");
291:   if (reason<0 && !q) PetscPrintf(PETSC_COMM_WORLD,"FAILED TO CONVERGE: stopping solve.\n");
292:   return(0);
293: }


296: /*=====================================================================
297:   PHYSICS FUNCTIONS (compute the discrete residual)
298:   =====================================================================*/


301: /*---------------------------------------------------------------------*/
304: PETSC_STATIC_INLINE PetscScalar UInterp(Field **x, PetscInt i, PetscInt j)
305: /*---------------------------------------------------------------------*/
306: {
307:   return 0.25*(x[j][i].u+x[j+1][i].u+x[j][i+1].u+x[j+1][i+1].u);
308: }

310: /*---------------------------------------------------------------------*/
313: PETSC_STATIC_INLINE PetscScalar WInterp(Field **x, PetscInt i, PetscInt j)
314: /*---------------------------------------------------------------------*/
315: {
316:   return 0.25*(x[j][i].w+x[j+1][i].w+x[j][i+1].w+x[j+1][i+1].w);
317: }

319: /*---------------------------------------------------------------------*/
322: PETSC_STATIC_INLINE PetscScalar PInterp(Field **x, PetscInt i, PetscInt j)
323: /*---------------------------------------------------------------------*/
324: {
325:   return 0.25*(x[j][i].p+x[j+1][i].p+x[j][i+1].p+x[j+1][i+1].p);
326: }

328: /*---------------------------------------------------------------------*/
331: PETSC_STATIC_INLINE PetscScalar TInterp(Field **x, PetscInt i, PetscInt j)
332: /*---------------------------------------------------------------------*/
333: {
334:   return 0.25*(x[j][i].T+x[j+1][i].T+x[j][i+1].T+x[j+1][i+1].T);
335: }

337: /*---------------------------------------------------------------------*/
340: /*  isoviscous analytic solution for IC */
341: PETSC_STATIC_INLINE PassiveScalar HorizVelocity(PetscInt i, PetscInt j, AppCtx *user)
342: /*---------------------------------------------------------------------*/
343: {
344:   Parameter   *param = user->param;
345:   GridInfo    *grid  = user->grid;
346:   PetscScalar x, z, r, st, ct, th, c=param->c, d=param->d;
347: 
348:   x = (i - grid->jlid)*grid->dx;  z = (j - grid->jlid - 0.5)*grid->dz;
349:   r = sqrt(x*x+z*z); st = z/r;  ct = x/r;  th = atan(z/x);
350:   return ct*(c*th*st+d*(st+th*ct)) + st*(c*(st-th*ct)+d*th*st);
351: }

353: /*---------------------------------------------------------------------*/
356: /*  isoviscous analytic solution for IC */
357: PETSC_STATIC_INLINE PetscScalar VertVelocity(PetscInt i, PetscInt j, AppCtx *user)
358: /*---------------------------------------------------------------------*/
359: {
360:   Parameter   *param = user->param;
361:   GridInfo    *grid  = user->grid;
362:   PetscScalar x, z, r, st, ct, th, c=param->c, d=param->d;
363: 
364:   x = (i - grid->jlid - 0.5)*grid->dx;  z = (j - grid->jlid)*grid->dz;
365:   r = sqrt(x*x+z*z); st = z/r;  ct = x/r;  th = atan(z/x);
366:   return st*(c*th*st+d*(st+th*ct)) - ct*(c*(st-th*ct)+d*th*st);
367: }

369: /*---------------------------------------------------------------------*/
372: /*  isoviscous analytic solution for IC */
373: PETSC_STATIC_INLINE PetscScalar Pressure(PetscInt i, PetscInt j, AppCtx *user)
374: /*---------------------------------------------------------------------*/
375: {
376:   Parameter   *param = user->param;
377:   GridInfo    *grid  = user->grid;
378:   PetscScalar x, z, r, st, ct, c=param->c, d=param->d;

380:   x = (i - grid->jlid - 0.5)*grid->dx;  z = (j - grid->jlid - 0.5)*grid->dz;
381:   r = sqrt(x*x+z*z);  st = z/r;  ct = x/r;
382:   return (-2.0*(c*ct-d*st)/r);
383: }

387: /*  computes the second invariant of the strain rate tensor */
388: PETSC_STATIC_INLINE PetscScalar CalcSecInv(Field **x, PetscInt i, PetscInt j, PetscInt ipos, AppCtx *user)
389: /*---------------------------------------------------------------------*/
390: {
391:   Parameter     *param = user->param;
392:   GridInfo      *grid  = user->grid;
393:   PetscInt           ilim=grid->ni-1, jlim=grid->nj-1;
394:   PetscScalar   uN,uS,uE,uW,wN,wS,wE,wW;
395:   PetscScalar   eps11, eps12, eps22;

397:   if (i<j) return EPS_ZERO;
398:   if (i==ilim) i--; if (j==jlim) j--;

400:   if (ipos==CELL_CENTER) { /* on cell center */
401:     if (j<=grid->jlid) return EPS_ZERO;

403:     uE = x[j][i].u; uW = x[j][i-1].u;
404:     wN = x[j][i].w; wS = x[j-1][i].w;
405:     wE = WInterp(x,i,j-1);
406:     if (i==j) { uN = param->cb; wW = param->sb; }
407:     else      { uN = UInterp(x,i-1,j); wW = WInterp(x,i-1,j-1); }

409:     if (j==grid->jlid+1) uS = 0.0;
410:     else                 uS = UInterp(x,i-1,j-1);

412:   } else {       /* on CELL_CORNER */
413:     if (j<grid->jlid) return EPS_ZERO;

415:     uN = x[j+1][i].u;  uS = x[j][i].u;
416:     wE = x[j][i+1].w;  wW = x[j][i].w;
417:     if (i==j) { wN = param->sb; uW = param->cb; }
418:     else      { wN = WInterp(x,i,j); uW = UInterp(x,i-1,j); }

420:     if (j==grid->jlid) {
421:       uE = 0.0;  uW = 0.0;
422:       uS = -uN;
423:       wS = -wN;
424:     } else {
425:       uE = UInterp(x,i,j);
426:       wS = WInterp(x,i,j-1);
427:     }
428:   }

430:   eps11 = (uE-uW)/grid->dx;  eps22 = (wN-wS)/grid->dz;
431:   eps12 = 0.5*((uN-uS)/grid->dz + (wE-wW)/grid->dx);

433:   return sqrt( 0.5*( eps11*eps11 + 2.0*eps12*eps12 + eps22*eps22 ) );
434: }

436: /*---------------------------------------------------------------------*/
439: /*  computes the shear viscosity */
440: PETSC_STATIC_INLINE PetscScalar Viscosity(PetscScalar T, PetscScalar eps, PassiveScalar z, Parameter *param)
441: /*---------------------------------------------------------------------*/
442: {
443:   PetscReal    result=0.0;
444:   ViscParam    difn=param->diffusion, disl=param->dislocation;
445:   PetscInt          iVisc=param->ivisc;
446:   double       eps_scale=param->V/(param->L*1000.0);
447:   double       strain_power, v1, v2, P;
448:   double       rho_g = 32340.0, R=8.3144;

450:   P = rho_g*(z*param->L*1000.0); /* Pa */

452:   if        (iVisc==VISC_CONST) {
453:     /* constant viscosity */
454:     return 1.0;

456:   } else if (iVisc==VISC_DIFN) {
457:     /* diffusion creep rheology */
458:     result = difn.A*PetscExpScalar((difn.Estar + P*difn.Vstar)/R/(T+273.0))/param->eta0;

460:   } else if (iVisc==VISC_DISL) {
461:     /* dislocation creep rheology */
462:     strain_power = pow( eps*eps_scale, (1.0-disl.n)/disl.n );
463:     result = disl.A*PetscExpScalar((disl.Estar + P*disl.Vstar)/disl.n/R/(T+273.0))*strain_power/param->eta0;

465:   } else if (iVisc==VISC_FULL) {
466:     /* dislocation/diffusion creep rheology */
467:     strain_power = pow( eps*eps_scale, (1.0-disl.n)/disl.n );
468:     v1 = difn.A*PetscExpScalar((difn.Estar + P*difn.Vstar)/R/(T+273.0))/param->eta0;
469:     v2 = disl.A*PetscExpScalar((disl.Estar + P*disl.Vstar)/disl.n/R/(T+273.0))*strain_power/param->eta0;
470:     result = 1.0/(1.0/v1 + 1.0/v2);
471:   }

473:   /* max viscosity is param->eta0 */
474:   result = PetscMin( result, 1.0 );
475:   /* min viscosity is param->visc_cutoff */
476:   result = PetscMax( result, param->visc_cutoff );
477:   /* continuation method */
478:   result = pow(result,param->continuation);
479:   return result;
480: }

482: /*---------------------------------------------------------------------*/
485: /*  computes the residual of the x-component of eqn (1) above */
486: PETSC_STATIC_INLINE PetscScalar XMomentumResidual(Field **x, PetscInt i, PetscInt j, AppCtx *user)
487: /*---------------------------------------------------------------------*/
488: {
489:   Parameter      *param=user->param;
490:   GridInfo       *grid =user->grid;
491:   PetscScalar    dx = grid->dx, dz=grid->dz;
492:   PetscScalar    etaN,etaS,etaE,etaW,epsN=0.0,epsS=0.0,epsE=0.0,epsW=0.0;
493:   PetscScalar    TE=0.0,TN=0.0,TS=0.0,TW=0.0, dPdx, residual, z_scale;
494:   PetscScalar    dudxW,dudxE,dudzN,dudzS,dwdxN,dwdxS;
495:   PetscInt            jlim = grid->nj-1;

497:   z_scale = param->z_scale;

499:   if ( param->ivisc==VISC_DIFN || param->ivisc>=VISC_DISL ) { /* viscosity is T-dependent */
500:     TS = param->potentialT * TInterp(x,i,j-1) * exp( (j-1.0)*dz*z_scale );
501:     if (j==jlim) TN = TS;
502:     else         TN = param->potentialT * TInterp(x,i,j)   * exp(  j     *dz*z_scale );
503:     TW = param->potentialT * x[j][i].T        * exp( (j-0.5)*dz*z_scale );
504:     TE = param->potentialT * x[j][i+1].T      * exp( (j-0.5)*dz*z_scale );
505:     if (param->ivisc>=VISC_DISL) { /* olivine dislocation creep */
506:       epsN = CalcSecInv(x,i,j,  CELL_CORNER,user);
507:       epsS = CalcSecInv(x,i,j-1,CELL_CORNER,user);
508:       epsE = CalcSecInv(x,i+1,j,CELL_CENTER,user);
509:       epsW = CalcSecInv(x,i,j,  CELL_CENTER,user);
510:     }
511:   }
512:   etaN = Viscosity(TN,epsN,dz*(j+0.5),param);
513:   etaS = Viscosity(TS,epsS,dz*(j-0.5),param);
514:   etaW = Viscosity(TW,epsW,dz*j,param);
515:   etaE = Viscosity(TE,epsE,dz*j,param);

517:   dPdx = ( x[j][i+1].p - x[j][i].p )/dx;
518:   if (j==jlim) dudzN = etaN * ( x[j][i].w   - x[j][i+1].w )/dx;
519:   else         dudzN = etaN * ( x[j+1][i].u - x[j][i].u   )/dz;
520:   dudzS = etaS * ( x[j][i].u    - x[j-1][i].u )/dz;
521:   dudxE = etaE * ( x[j][i+1].u  - x[j][i].u   )/dx;
522:   dudxW = etaW * ( x[j][i].u    - x[j][i-1].u )/dx;

524:   residual  = -dPdx                         /* X-MOMENTUM EQUATION*/
525:               +( dudxE - dudxW )/dx
526:               +( dudzN - dudzS )/dz;

528:   if ( param->ivisc!=VISC_CONST ) {
529:     dwdxN = etaN * ( x[j][i+1].w   - x[j][i].w   )/dx;
530:     dwdxS = etaS * ( x[j-1][i+1].w - x[j-1][i].w )/dx;

532:     residual += ( dudxE - dudxW )/dx + ( dwdxN - dwdxS )/dz;
533:   }

535:   return residual;
536: }

538: /*---------------------------------------------------------------------*/
541: /*  computes the residual of the z-component of eqn (1) above */
542: PETSC_STATIC_INLINE PetscScalar ZMomentumResidual(Field **x, PetscInt i, PetscInt j, AppCtx *user)
543: /*---------------------------------------------------------------------*/
544: {
545:   Parameter      *param=user->param;
546:   GridInfo       *grid =user->grid;
547:   PetscScalar    dx = grid->dx, dz=grid->dz;
548:   PetscScalar    etaN=0.0,etaS=0.0,etaE=0.0,etaW=0.0,epsN=0.0,epsS=0.0,epsE=0.0,epsW=0.0;
549:   PetscScalar    TE=0.0,TN=0.0,TS=0.0,TW=0.0, dPdz, residual,z_scale;
550:   PetscScalar    dudzE,dudzW,dwdxW,dwdxE,dwdzN,dwdzS;
551:   PetscInt            ilim = grid->ni-1;

553:   /* geometric and other parameters */
554:   z_scale = param->z_scale;
555: 
556:   /* viscosity */
557:   if ( param->ivisc==VISC_DIFN || param->ivisc>=VISC_DISL ) { /* viscosity is T-dependent */
558:     TN = param->potentialT * x[j+1][i].T      * exp( (j+0.5)*dz*z_scale );
559:     TS = param->potentialT * x[j][i].T        * exp( (j-0.5)*dz*z_scale );
560:     TW = param->potentialT * TInterp(x,i-1,j) * exp(  j     *dz*z_scale );
561:     if (i==ilim) TE = TW;
562:     else         TE = param->potentialT * TInterp(x,i,j)   * exp(  j*dz*z_scale );
563:     if (param->ivisc>=VISC_DISL) { /* olivine dislocation creep */
564:       epsN = CalcSecInv(x,i,j+1,CELL_CENTER,user);
565:       epsS = CalcSecInv(x,i,j,  CELL_CENTER,user);
566:       epsE = CalcSecInv(x,i,j,  CELL_CORNER,user);
567:       epsW = CalcSecInv(x,i-1,j,CELL_CORNER,user);
568:     }
569:   }
570:   etaN = Viscosity(TN,epsN,dz*(j+1),param);
571:   etaS = Viscosity(TS,epsS,dz*j,param);
572:   etaW = Viscosity(TW,epsW,dz*(j+0.5),param);
573:   etaE = Viscosity(TE,epsE,dz*(j+0.5),param);

575:   dPdz = ( x[j+1][i].p - x[j][i].p )/dz;
576:   dwdzN = etaN * ( x[j+1][i].w - x[j][i].w )/dz;
577:   dwdzS = etaS * ( x[j][i].w - x[j-1][i].w )/dz;
578:   if (i==ilim) dwdxE = etaE * ( x[j][i].u   - x[j+1][i].u )/dz;
579:   else         dwdxE = etaE * ( x[j][i+1].w - x[j][i].w   )/dx;
580:   dwdxW = 2.0*etaW * ( x[j][i].w - x[j][i-1].w )/dx;
581: 
582:   /* Z-MOMENTUM */
583:   residual  = -dPdz                /* constant viscosity terms */
584:               +( dwdzN - dwdzS )/dz
585:               +( dwdxE - dwdxW )/dx;

587:   if ( param->ivisc!=VISC_CONST ) {
588:     dudzE = etaE * ( x[j+1][i].u - x[j][i].u )/dz;
589:     dudzW = etaW * ( x[j+1][i-1].u - x[j][i-1].u )/dz;

591:     residual += ( dwdzN - dwdzS )/dz + ( dudzE - dudzW )/dx;
592:   }

594:   return residual;
595: }

597: /*---------------------------------------------------------------------*/
600: /*  computes the residual of eqn (2) above */
601: PETSC_STATIC_INLINE PetscScalar ContinuityResidual(Field **x, PetscInt i, PetscInt j, AppCtx *user)
602: /*---------------------------------------------------------------------*/
603: {
604:   GridInfo       *grid =user->grid;
605:   PetscScalar    uE,uW,wN,wS,dudx,dwdz;

607:   uW = x[j][i-1].u; uE = x[j][i].u; dudx = ( uE - uW )/grid->dx;
608:   wS = x[j-1][i].w; wN = x[j][i].w; dwdz = ( wN - wS )/grid->dz;

610:   return dudx + dwdz;
611: }

613: /*---------------------------------------------------------------------*/
616: /*  computes the residual of eqn (3) above */
617: PETSC_STATIC_INLINE PetscScalar EnergyResidual(Field **x, PetscInt i, PetscInt j, AppCtx *user)
618: /*---------------------------------------------------------------------*/
619: {
620:   Parameter      *param=user->param;
621:   GridInfo       *grid =user->grid;
622:   PetscScalar    dx = grid->dx, dz=grid->dz;
623:   PetscInt            ilim=grid->ni-1, jlim=grid->nj-1, jlid=grid->jlid;
624:   PetscScalar    TE, TN, TS, TW, residual;
625:   PetscScalar    uE,uW,wN,wS;
626:   PetscScalar    fN,fS,fE,fW,dTdxW,dTdxE,dTdzN,dTdzS;

628:   dTdzN = ( x[j+1][i].T - x[j][i].T   )/dz;
629:   dTdzS = ( x[j][i].T   - x[j-1][i].T )/dz;
630:   dTdxE = ( x[j][i+1].T - x[j][i].T   )/dx;
631:   dTdxW = ( x[j][i].T   - x[j][i-1].T )/dx;
632: 
633:   residual = ( ( dTdzN - dTdzS )/dz + /* diffusion term */
634:                ( dTdxE - dTdxW )/dx  )*dx*dz/param->peclet;

636:   if (j<=jlid && i>=j) {
637:     /* don't advect in the lid */
638:     return residual;

640:   } else if (i<j) {
641:     /* beneath the slab sfc */
642:     uW = uE = param->cb;
643:     wS = wN = param->sb;

645:   } else {
646:     /* advect in the slab and wedge */
647:     uW = x[j][i-1].u; uE = x[j][i].u;
648:     wS = x[j-1][i].w; wN = x[j][i].w;
649:   }

651:   if ( param->adv_scheme==ADVECT_FV || i==ilim-1 || j==jlim-1 || i==1 || j==1 ) {
652:     /* finite volume advection */
653:     TS  = ( x[j][i].T + x[j-1][i].T )/2.0;
654:     TN  = ( x[j][i].T + x[j+1][i].T )/2.0;
655:     TE  = ( x[j][i].T + x[j][i+1].T )/2.0;
656:     TW  = ( x[j][i].T + x[j][i-1].T )/2.0;
657:     fN = wN*TN*dx; fS = wS*TS*dx;
658:     fE = uE*TE*dz; fW = uW*TW*dz;
659: 
660:   } else {
661:     /* Fromm advection scheme */
662:     fE =     ( uE *(-x[j][i+2].T + 5.0*(x[j][i+1].T+x[j][i].T)-x[j][i-1].T)/8.0
663:                - fabs(uE)*(-x[j][i+2].T + 3.0*(x[j][i+1].T-x[j][i].T)+x[j][i-1].T)/8.0 )*dz;
664:     fW =     ( uW *(-x[j][i+1].T + 5.0*(x[j][i].T+x[j][i-1].T)-x[j][i-2].T)/8.0
665:                - fabs(uW)*(-x[j][i+1].T + 3.0*(x[j][i].T-x[j][i-1].T)+x[j][i-2].T)/8.0 )*dz;
666:     fN =     ( wN *(-x[j+2][i].T + 5.0*(x[j+1][i].T+x[j][i].T)-x[j-1][i].T)/8.0
667:                - fabs(wN)*(-x[j+2][i].T + 3.0*(x[j+1][i].T-x[j][i].T)+x[j-1][i].T)/8.0 )*dx;
668:     fS =     ( wS *(-x[j+1][i].T + 5.0*(x[j][i].T+x[j-1][i].T)-x[j-2][i].T)/8.0
669:                - fabs(wS)*(-x[j+1][i].T + 3.0*(x[j][i].T-x[j-1][i].T)+x[j-2][i].T)/8.0 )*dx;
670:   }
671: 
672:   residual -= ( fE - fW + fN - fS );

674:   return residual;
675: }

677: /*---------------------------------------------------------------------*/
680: /*  computes the shear stress---used on the boundaries */
681: PETSC_STATIC_INLINE PetscScalar ShearStress(Field **x, PetscInt i, PetscInt j, PetscInt ipos, AppCtx *user)
682: /*---------------------------------------------------------------------*/
683: {
684:   Parameter    *param=user->param;
685:   GridInfo     *grid=user->grid;
686:   PetscInt          ilim=grid->ni-1, jlim=grid->nj-1;
687:   PetscScalar  uN, uS, wE, wW;

689:   if ( j<=grid->jlid || i<j || i==ilim || j==jlim ) return EPS_ZERO;

691:   if (ipos==CELL_CENTER) { /* on cell center */

693:     wE = WInterp(x,i,j-1);
694:     if (i==j) { wW = param->sb; uN = param->cb;}
695:     else      { wW = WInterp(x,i-1,j-1); uN = UInterp(x,i-1,j); }
696:     if (j==grid->jlid+1)  uS = 0.0;
697:     else                  uS = UInterp(x,i-1,j-1);

699:   } else { /* on cell corner */

701:     uN = x[j+1][i].u;         uS = x[j][i].u;
702:     wW = x[j][i].w;           wE = x[j][i+1].w;

704:   }

706:   return (uN-uS)/grid->dz + (wE-wW)/grid->dx;
707: }

709: /*---------------------------------------------------------------------*/
712: /*  computes the normal stress---used on the boundaries */
713: PETSC_STATIC_INLINE PetscScalar XNormalStress(Field **x, PetscInt i, PetscInt j, PetscInt ipos, AppCtx *user)
714: /*---------------------------------------------------------------------*/
715: {
716:   Parameter      *param=user->param;
717:   GridInfo       *grid =user->grid;
718:   PetscScalar    dx = grid->dx, dz=grid->dz;
719:   PetscInt            ilim=grid->ni-1, jlim=grid->nj-1, ivisc;
720:   PetscScalar    epsC=0.0, etaC, TC, uE, uW, pC, z_scale;
721:   if (i<j || j<=grid->jlid) return EPS_ZERO;

723:   ivisc=param->ivisc;  z_scale = param->z_scale;

725:   if (ipos==CELL_CENTER) { /* on cell center */

727:     TC = param->potentialT * x[j][i].T * exp( (j-0.5)*dz*z_scale );
728:     if (ivisc>=VISC_DISL) epsC = CalcSecInv(x,i,j,CELL_CENTER,user);
729:     etaC = Viscosity(TC,epsC,dz*j,param);

731:     uW = x[j][i-1].u;   uE = x[j][i].u;
732:     pC = x[j][i].p;

734:   } else { /* on cell corner */
735:     if ( i==ilim || j==jlim ) return EPS_ZERO;

737:     TC = param->potentialT * TInterp(x,i,j) * exp( j*dz*z_scale );
738:     if (ivisc>=VISC_DISL) epsC = CalcSecInv(x,i,j,CELL_CORNER,user);
739:     etaC = Viscosity(TC,epsC,dz*(j+0.5),param);

741:     if (i==j) uW = param->sb;
742:     else      uW = UInterp(x,i-1,j);
743:     uE = UInterp(x,i,j); pC = PInterp(x,i,j);
744:   }
745: 
746:   return 2.0*etaC*(uE-uW)/dx - pC;
747: }

749: /*---------------------------------------------------------------------*/
752: /*  computes the normal stress---used on the boundaries */
753: PETSC_STATIC_INLINE PetscScalar ZNormalStress(Field **x, PetscInt i, PetscInt j, PetscInt ipos, AppCtx *user)
754: /*---------------------------------------------------------------------*/
755: {
756:   Parameter      *param=user->param;
757:   GridInfo       *grid =user->grid;
758:   PetscScalar    dz=grid->dz;
759:   PetscInt            ilim=grid->ni-1, jlim=grid->nj-1, ivisc;
760:   PetscScalar    epsC=0.0, etaC, TC;
761:   PetscScalar    pC, wN, wS, z_scale;
762:   if (i<j || j<=grid->jlid) return EPS_ZERO;

764:   ivisc=param->ivisc;  z_scale = param->z_scale;

766:   if (ipos==CELL_CENTER) { /* on cell center */

768:     TC = param->potentialT * x[j][i].T * exp( (j-0.5)*dz*z_scale );
769:     if (ivisc>=VISC_DISL) epsC = CalcSecInv(x,i,j,CELL_CENTER,user);
770:     etaC = Viscosity(TC,epsC,dz*j,param);
771:     wN = x[j][i].w; wS = x[j-1][i].w; pC = x[j][i].p;

773:   } else { /* on cell corner */
774:     if ( (i==ilim) || (j==jlim) ) return EPS_ZERO;

776:     TC = param->potentialT * TInterp(x,i,j) * exp( j*dz*z_scale );
777:     if (ivisc>=VISC_DISL) epsC = CalcSecInv(x,i,j,CELL_CORNER,user);
778:     etaC = Viscosity(TC,epsC,dz*(j+0.5),param);
779:     if (i==j) wN = param->sb;
780:     else      wN = WInterp(x,i,j);
781:     wS = WInterp(x,i,j-1); pC = PInterp(x,i,j);
782:   }

784:   return  2.0*etaC*(wN-wS)/dz - pC;
785: }

787: /*---------------------------------------------------------------------*/

789: /*=====================================================================
790:   INITIALIZATION, POST-PROCESSING AND OUTPUT FUNCTIONS 
791:   =====================================================================*/

793: /*---------------------------------------------------------------------*/
796: /* initializes the problem parameters and checks for 
797:    command line changes */
798: PetscErrorCode SetParams(Parameter *param, GridInfo *grid)
799: /*---------------------------------------------------------------------*/
800: {
801:   PetscErrorCode ierr, ierr_out=0;
802:   PetscReal      SEC_PER_YR = 3600.00*24.00*365.2500;
803:   PetscReal      PI = 3.14159265358979323846;
804:   PetscReal      alpha_g_on_cp_units_inverse_km=4.0e-5*9.8;
805: 
806:   /* domain geometry */
807:   param->slab_dip      = 45.0;
808:   param->width         = 320.0;                                            /* km */
809:   param->depth         = 300.0;                                            /* km */
810:   param->lid_depth     = 35.0;                                             /* km */
811:   param->fault_depth   = 35.0;                                             /* km */
812:   PetscOptionsGetReal(PETSC_NULL,"-slab_dip",&(param->slab_dip),PETSC_NULL);
813:   PetscOptionsGetReal(PETSC_NULL,"-width",&(param->width),PETSC_NULL);
814:   PetscOptionsGetReal(PETSC_NULL,"-depth",&(param->depth),PETSC_NULL);
815:   PetscOptionsGetReal(PETSC_NULL,"-lid_depth",&(param->lid_depth),PETSC_NULL);
816:   PetscOptionsGetReal(PETSC_NULL,"-fault_depth",&(param->fault_depth),PETSC_NULL);
817:   param->slab_dip      = param->slab_dip*PI/180.0;                    /* radians */

819:   /* grid information */
820:   PetscOptionsGetInt(PETSC_NULL, "-jfault",&(grid->jfault),PETSC_NULL);
821:   grid->ni             = 82;
822:   PetscOptionsGetInt(PETSC_NULL, "-ni",&(grid->ni),PETSC_NULL);
823:   grid->dx             = param->width/((double)(grid->ni-2));              /* km */
824:   grid->dz             = grid->dx*tan(param->slab_dip);                    /* km */
825:   grid->nj             = (PetscInt)(param->depth/grid->dz + 3.0);        /* gridpoints*/
826:   param->depth         = grid->dz*(grid->nj-2);                            /* km */
827:   grid->inose          = 0;                                         /* gridpoints*/
828:   PetscOptionsGetInt(PETSC_NULL,"-inose",&(grid->inose),PETSC_NULL);
829:   grid->bx       = DMDA_BOUNDARY_NONE;
830:   grid->by       = DMDA_BOUNDARY_NONE;
831:   grid->stencil        = DMDA_STENCIL_BOX;
832:   grid->dof            = 4;
833:   grid->stencil_width  = 2;
834:   grid->mglevels       = 1;

836:   /* boundary conditions */
837:   param->pv_analytic        = PETSC_FALSE;
838:   param->ibound             = BC_NOSTRESS;
839:   PetscOptionsGetInt(PETSC_NULL,"-ibound",&(param->ibound),PETSC_NULL);

841:   /* physical constants */
842:   param->slab_velocity = 5.0;               /* cm/yr */
843:   param->slab_age      = 50.0;              /* Ma */
844:   param->lid_age       = 50.0;              /* Ma */
845:   param->kappa         = 0.7272e-6;         /* m^2/sec */
846:   param->potentialT    = 1300.0;            /* degrees C */
847:   PetscOptionsGetReal(PETSC_NULL,"-slab_velocity",&(param->slab_velocity),PETSC_NULL);
848:   PetscOptionsGetReal(PETSC_NULL,"-slab_age",&(param->slab_age),PETSC_NULL);
849:   PetscOptionsGetReal(PETSC_NULL,"-lid_age",&(param->lid_age),PETSC_NULL);
850:   PetscOptionsGetReal(PETSC_NULL,"-kappa",&(param->kappa),PETSC_NULL);
851:   PetscOptionsGetReal(PETSC_NULL,"-potentialT",&(param->potentialT),PETSC_NULL);

853:   /* viscosity */
854:   param->ivisc         = 3;                 /* 0=isovisc, 1=difn creep, 2=disl creep, 3=full */
855:   param->eta0          = 1e24;              /* Pa-s */
856:   param->visc_cutoff   = 0.0;               /* factor of eta_0 */
857:   param->continuation  = 1.0;
858:   /* constants for diffusion creep */
859:   param->diffusion.A       = 1.8e7;           /* Pa-s */
860:   param->diffusion.n       = 1.0;             /* dim'less */
861:   param->diffusion.Estar   = 375e3;           /* J/mol */
862:   param->diffusion.Vstar   = 5e-6;            /* m^3/mol */
863:   /* constants for param->dislocationocation creep */
864:   param->dislocation.A     = 2.8969e4;        /* Pa-s */
865:   param->dislocation.n     = 3.5;             /* dim'less */
866:   param->dislocation.Estar = 530e3;           /* J/mol */
867:   param->dislocation.Vstar = 14e-6;           /* m^3/mol */
868:   PetscOptionsGetInt(PETSC_NULL, "-ivisc",&(param->ivisc),PETSC_NULL);
869:   PetscOptionsGetReal(PETSC_NULL,"-visc_cutoff",&(param->visc_cutoff),PETSC_NULL);
870:   param->output_ivisc  = param->ivisc;
871:   PetscOptionsGetInt(PETSC_NULL,"-output_ivisc",&(param->output_ivisc),PETSC_NULL);
872:   PetscOptionsGetReal(PETSC_NULL,"-vstar",&(param->dislocation.Vstar),PETSC_NULL);

874:   /* output options */
875:   param->quiet            = PETSC_FALSE;
876:   param->param_test       = PETSC_FALSE;
877:   PetscOptionsHasName(PETSC_NULL,"-quiet",&(param->quiet));
878:   PetscOptionsHasName(PETSC_NULL,"-test",&(param->param_test));
879:   PetscOptionsGetString(PETSC_NULL,"-file",param->filename,PETSC_MAX_PATH_LEN,&(param->output_to_file));

881:   /* advection */
882:   param->adv_scheme       = ADVECT_FROMM;       /* advection scheme: 0=finite vol, 1=Fromm */
883:   PetscOptionsGetInt(PETSC_NULL,"-adv_scheme",&(param->adv_scheme),PETSC_NULL);

885:   /* misc. flags */
886:   param->stop_solve          = PETSC_FALSE;
887:   param->interrupted         = PETSC_FALSE;
888:   param->kspmon              = PETSC_FALSE;
889:   param->toggle_kspmon       = PETSC_FALSE;

891:   /* derived parameters for slab angle */
892:   param->sb  = sin(param->slab_dip);
893:   param->cb  = cos(param->slab_dip);
894:   param->c   =  param->slab_dip*param->sb/(param->slab_dip*param->slab_dip-param->sb*param->sb);
895:   param->d   = (param->slab_dip*param->cb-param->sb)/(param->slab_dip*param->slab_dip-param->sb*param->sb);

897:   /* length, velocity and time scale for non-dimensionalization */
898:   param->L = PetscMin(param->width,param->depth);               /* km */
899:   param->V = param->slab_velocity/100.0/SEC_PER_YR;             /* m/sec */

901:   /* other unit conversions and derived parameters */
902:   param->scaled_width  = param->width/param->L;                 /* dim'less */
903:   param->scaled_depth  = param->depth/param->L;                 /* dim'less */
904:   param->lid_depth     = param->lid_depth/param->L;             /* dim'less */
905:   param->fault_depth   = param->fault_depth/param->L;           /* dim'less */
906:   grid->dx             = grid->dx/param->L;                     /* dim'less */
907:   grid->dz             = grid->dz/param->L;                     /* dim'less */
908:   grid->jlid           = (PetscInt)(param->lid_depth/grid->dz);      /* gridcells */
909:   grid->jfault         = (PetscInt)(param->fault_depth/grid->dz);    /* gridcells */
910:   param->lid_depth     = grid->jlid*grid->dz;                   /* dim'less */
911:   param->fault_depth   = grid->jfault*grid->dz;                 /* dim'less */
912:   grid->corner         = grid->jlid+1;                          /* gridcells */
913:   param->peclet        = param->V                               /* m/sec */
914:                        * param->L*1000.0                        /* m */
915:                        / param->kappa;                          /* m^2/sec */
916:   param->z_scale       = param->L * alpha_g_on_cp_units_inverse_km;
917:   param->skt           = sqrt(param->kappa*param->slab_age*SEC_PER_YR);
918:   PetscOptionsGetReal(PETSC_NULL,"-peclet",&(param->peclet),PETSC_NULL);
919: 
920:   return ierr_out;
921: }

923: /*---------------------------------------------------------------------*/
926: /*  prints a report of the problem parameters to stdout */
927: PetscErrorCode ReportParams(Parameter *param, GridInfo *grid)
928: /*---------------------------------------------------------------------*/
929: {
930:   PetscErrorCode ierr, ierr_out=0;
931:   char           date[30];
932:   PetscReal      PI = 3.14159265358979323846;

934:   PetscGetDate(date,30);

936:   if ( !(param->quiet) ) {
937:     PetscPrintf(PETSC_COMM_WORLD,"---------------------BEGIN ex30 PARAM REPORT-------------------\n");
938:     /* PetscPrintf(PETSC_COMM_WORLD,"                   %s\n",&(date[0]));*/

940:     PetscPrintf(PETSC_COMM_WORLD,"Domain: \n");
941:     PetscPrintf(PETSC_COMM_WORLD,"  Width = %G km,         Depth = %G km\n",param->width,param->depth);
942:     PetscPrintf(PETSC_COMM_WORLD,"  Slab dip = %G degrees,  Slab velocity = %G cm/yr\n",param->slab_dip*180.0/PI,param->slab_velocity);
943:     PetscPrintf(PETSC_COMM_WORLD,"  Lid depth = %5.2f km,   Fault depth = %5.2f km\n",param->lid_depth*param->L,param->fault_depth*param->L);

945:     PetscPrintf(PETSC_COMM_WORLD,"\nGrid: \n");
946:     PetscPrintf(PETSC_COMM_WORLD,"  [ni,nj] = %D, %D       [dx,dz] = %G, %G km\n",grid->ni,grid->nj,grid->dx*param->L,grid->dz*param->L);
947:     PetscPrintf(PETSC_COMM_WORLD,"  jlid = %3D              jfault = %3D \n",grid->jlid,grid->jfault);
948:     PetscPrintf(PETSC_COMM_WORLD,"  Pe = %G\n",param->peclet);

950:     PetscPrintf(PETSC_COMM_WORLD,"\nRheology:");
951:     if (param->ivisc==VISC_CONST) {
952:       PetscPrintf(PETSC_COMM_WORLD,"                 Isoviscous \n");
953:       if (param->pv_analytic)
954:         PetscPrintf(PETSC_COMM_WORLD,"                          Pressure and Velocity prescribed! \n");
955:     } else if (param->ivisc==VISC_DIFN) {
956:       PetscPrintf(PETSC_COMM_WORLD,"                 Diffusion Creep (T-Dependent Newtonian) \n");
957:       PetscPrintf(PETSC_COMM_WORLD,"                          Viscosity range: %G--%G Pa-sec \n",param->eta0,param->visc_cutoff*param->eta0);
958:     } else if (param->ivisc==VISC_DISL ) {
959:       PetscPrintf(PETSC_COMM_WORLD,"                 Dislocation Creep (T-Dependent Non-Newtonian) \n");
960:       PetscPrintf(PETSC_COMM_WORLD,"                          Viscosity range: %G--%G Pa-sec \n",param->eta0,param->visc_cutoff*param->eta0);
961:     } else if (param->ivisc==VISC_FULL ) {
962:       PetscPrintf(PETSC_COMM_WORLD,"                 Full Rheology \n");
963:       PetscPrintf(PETSC_COMM_WORLD,"                          Viscosity range: %G--%G Pa-sec \n",param->eta0,param->visc_cutoff*param->eta0);
964:     } else {
965:       PetscPrintf(PETSC_COMM_WORLD,"                 Invalid! \n");
966:       ierr_out=1;
967:     }

969:     PetscPrintf(PETSC_COMM_WORLD,"Boundary condition:");
970:     if ( param->ibound==BC_ANALYTIC ) {
971:       PetscPrintf(PETSC_COMM_WORLD,"       Isoviscous Analytic Dirichlet \n");
972:     } else if ( param->ibound==BC_NOSTRESS ) {
973:       PetscPrintf(PETSC_COMM_WORLD,"       Stress-Free (normal & shear stress)\n");
974:     } else if ( param->ibound==BC_EXPERMNT ) {
975:       PetscPrintf(PETSC_COMM_WORLD,"       Experimental boundary condition \n");
976:     } else {
977:       PetscPrintf(PETSC_COMM_WORLD,"       Invalid! \n");
978:       ierr_out=1;
979:     }

981:     if (param->output_to_file)
982: #if defined(PETSC_HAVE_MATLAB_ENGINE)
983:       PetscPrintf(PETSC_COMM_WORLD,"Output Destination:       Mat file \"%s\"\n",param->filename);
984: #else
985:       PetscPrintf(PETSC_COMM_WORLD,"Output Destination:       PETSc binary file \"%s\"\n",param->filename);
986: #endif
987:     if ( param->output_ivisc != param->ivisc )
988:       PetscPrintf(PETSC_COMM_WORLD,"                          Output viscosity: -ivisc %D\n",param->output_ivisc);

990:     PetscPrintf(PETSC_COMM_WORLD,"---------------------END ex30 PARAM REPORT---------------------\n");
991:   }
992:   if ( param->param_test ) PetscEnd();
993:   return ierr_out;
994: }

996: /* ------------------------------------------------------------------- */
999: /*  generates an inital guess using the analytic solution for isoviscous
1000:     corner flow */
1001: PetscErrorCode Initialize(DM da)
1002: /* ------------------------------------------------------------------- */
1003: {
1004:   AppCtx         *user;
1005:   Parameter      *param;
1006:   GridInfo       *grid;
1007:   PetscInt       i,j,is,js,im,jm;
1009:   Field          **x;
1010:   Vec            Xguess;

1012:   /* Get the fine grid */
1013:   DMGetApplicationContext(da,&user);
1014:   Xguess = user->Xguess;
1015:   param = user->param;
1016:   grid  = user->grid;
1017:   DMDAGetCorners(da,&is,&js,PETSC_NULL,&im,&jm,PETSC_NULL);
1018:   DMDAVecGetArray(da,Xguess,(void**)&x);

1020:   /* Compute initial guess */
1021:   for (j=js; j<js+jm; j++) {
1022:     for (i=is; i<is+im; i++) {
1023:       if (i<j) {
1024:         x[j][i].u  = param->cb;
1025:       } else if (j<=grid->jlid) {
1026:         x[j][i].u  = 0.0;
1027:       } else {
1028:         x[j][i].u  = HorizVelocity(i,j,user);
1029:       }
1030:       if (i<=j) {
1031:         x[j][i].w = param->sb;
1032:       } else if (j<=grid->jlid) {
1033:         x[j][i].w = 0.0;
1034:       } else {
1035:         x[j][i].w = VertVelocity(i,j,user);
1036:       }
1037:       if (i<j || j<=grid->jlid) {
1038:         x[j][i].p = 0.0;
1039:       } else {
1040:         x[j][i].p = Pressure(i,j,user);
1041:       }
1042:       x[j][i].T   = PetscMin(grid->dz*(j-0.5),1.0);
1043:     }
1044:   }

1046:   /* Restore x to Xguess */
1047:   DMDAVecRestoreArray(da,Xguess,(void**)&x);

1049:   return 0;
1050: }

1052: /*---------------------------------------------------------------------*/
1055: /*  controls output to a file */
1056: PetscErrorCode DoOutput(SNES snes, PetscInt its)
1057: /*---------------------------------------------------------------------*/
1058: {
1059:   AppCtx         *user;
1060:   Parameter      *param;
1061:   GridInfo       *grid;
1062:   PetscInt       ivt;
1064:   PetscMPIInt    rank;
1065:   PetscViewer    viewer;
1066:   Vec            res, pars;
1067:   MPI_Comm       comm;
1068:   DM             da;

1070:   SNESGetDM(snes,&da);
1071:   DMGetApplicationContext(da,&user);
1072:   param = user->param;
1073:   grid  = user->grid;
1074:   ivt   = param->ivisc;

1076:   param->ivisc = param->output_ivisc;

1078:   /* compute final residual and final viscosity/strain rate fields */
1079:   SNESGetFunction(snes, &res, PETSC_NULL, PETSC_NULL);
1080:   ViscosityField(da, user->x, user->Xguess);

1082:   /* get the communicator and the rank of the processor */
1083:   PetscObjectGetComm((PetscObject)snes, &comm);
1084:   MPI_Comm_rank(comm, &rank);

1086:   if (param->output_to_file) { /* send output to binary file */
1087:     VecCreate(comm, &pars);
1088:     if (rank == 0) { /* on processor 0 */
1089:       VecSetSizes(pars, 20, PETSC_DETERMINE);
1090:       VecSetFromOptions(pars);
1091:       VecSetValue(pars,0, (PetscScalar)(grid->ni),INSERT_VALUES);
1092:       VecSetValue(pars,1, (PetscScalar)(grid->nj),INSERT_VALUES);
1093:       VecSetValue(pars,2, (PetscScalar)(grid->dx),INSERT_VALUES);
1094:       VecSetValue(pars,3, (PetscScalar)(grid->dz),INSERT_VALUES);
1095:       VecSetValue(pars,4, (PetscScalar)(param->L),INSERT_VALUES);
1096:       VecSetValue(pars,5, (PetscScalar)(param->V),INSERT_VALUES);
1097:       /* skipped 6 intentionally */
1098:       VecSetValue(pars,7, (PetscScalar)(param->slab_dip),INSERT_VALUES);
1099:       VecSetValue(pars,8, (PetscScalar)(grid->jlid),INSERT_VALUES);
1100:       VecSetValue(pars,9, (PetscScalar)(param->lid_depth),INSERT_VALUES);
1101:       VecSetValue(pars,10,(PetscScalar)(grid->jfault),INSERT_VALUES);
1102:       VecSetValue(pars,11,(PetscScalar)(param->fault_depth),INSERT_VALUES);
1103:       VecSetValue(pars,12,(PetscScalar)(param->potentialT),INSERT_VALUES);
1104:       VecSetValue(pars,13,(PetscScalar)(param->ivisc),INSERT_VALUES);
1105:       VecSetValue(pars,14,(PetscScalar)(param->visc_cutoff),INSERT_VALUES);
1106:       VecSetValue(pars,15,(PetscScalar)(param->ibound),INSERT_VALUES);
1107:       VecSetValue(pars,16,(PetscScalar)(its),INSERT_VALUES);
1108:     } else { /* on some other processor */
1109:       VecSetSizes(pars, 0, PETSC_DETERMINE);
1110:       VecSetFromOptions(pars);
1111:     }
1112:     VecAssemblyBegin(pars); VecAssemblyEnd(pars);

1114:     /* create viewer */
1115: #if defined(PETSC_HAVE_MATLAB_ENGINE)
1116:     PetscViewerMatlabOpen(PETSC_COMM_WORLD,param->filename,FILE_MODE_WRITE,&viewer);
1117: #else
1118:     PetscViewerBinaryOpen(PETSC_COMM_WORLD,param->filename,FILE_MODE_WRITE,&viewer);
1119: #endif

1121:     /* send vectors to viewer */
1122:     PetscObjectSetName((PetscObject)res,"res");
1123:     VecView(res,viewer);
1124:     PetscObjectSetName((PetscObject)user->x,"out");
1125:     VecView(user->x, viewer);
1126:     PetscObjectSetName((PetscObject)(user->Xguess),"aux");
1127:     VecView(user->Xguess, viewer);
1128:     StressField(da); /* compute stress fields */
1129:     PetscObjectSetName((PetscObject)(user->Xguess),"str");
1130:     VecView(user->Xguess, viewer);
1131:     PetscObjectSetName((PetscObject)pars,"par");
1132:     VecView(pars, viewer);
1133: 
1134:     /* destroy viewer and vector */
1135:     PetscViewerDestroy(&viewer);
1136:     VecDestroy(&pars);
1137:   }
1138: 
1139:   param->ivisc = ivt;
1140:   return 0;
1141: }

1143: /* ------------------------------------------------------------------- */
1146: /* Compute both the second invariant of the strain rate tensor and the viscosity, at both cell centers and cell corners */
1147: PetscErrorCode ViscosityField(DM da, Vec X, Vec V)
1148: /* ------------------------------------------------------------------- */
1149: {
1150:   AppCtx         *user;
1151:   Parameter      *param;
1152:   GridInfo       *grid;
1153:   Vec            localX;
1154:   Field          **v, **x;
1155:   PassiveReal    eps, /* dx,*/ dz, T, epsC, TC;
1156:   PetscInt       i,j,is,js,im,jm,ilim,jlim,ivt;

1160:   DMGetApplicationContext(da,&user);
1161:   param = user->param;
1162:   grid  = user->grid;
1163:   ivt          = param->ivisc;
1164:   param->ivisc = param->output_ivisc;

1166:   DMGetLocalVector(da, &localX);
1167:   DMGlobalToLocalBegin(da, X, INSERT_VALUES, localX);
1168:   DMGlobalToLocalEnd(da, X, INSERT_VALUES, localX);
1169:   DMDAVecGetArray(da,localX,(void**)&x);
1170:   DMDAVecGetArray(da,V,(void**)&v);

1172:   /* Parameters */
1173:   /* dx = grid->dx; */ dz   = grid->dz;
1174:   ilim = grid->ni-1; jlim = grid->nj-1;

1176:   /* Compute real temperature, strain rate and viscosity */
1177:   DMDAGetCorners(da,&is,&js,PETSC_NULL,&im,&jm,PETSC_NULL);
1178:   for (j=js; j<js+jm; j++) {
1179:     for (i=is; i<is+im; i++) {
1180:       T  = param->potentialT * x[j][i].T * exp( (j-0.5)*dz*param->z_scale );
1181:       if (i<ilim && j<jlim) {
1182:         TC = param->potentialT * TInterp(x,i,j) * exp( j*dz*param->z_scale );
1183:       } else {
1184:         TC = T;
1185:       }
1186:       eps  = CalcSecInv(x,i,j,CELL_CENTER,user);
1187:       epsC = CalcSecInv(x,i,j,CELL_CORNER,user);
1188:       v[j][i].u = eps;
1189:       v[j][i].w = epsC;
1190:       v[j][i].p = Viscosity(T,eps,dz*(j-0.5),param);
1191:       v[j][i].T = Viscosity(TC,epsC,dz*j,param);
1192:     }
1193:   }
1194:   DMDAVecRestoreArray(da,V,(void**)&v);
1195:   DMDAVecRestoreArray(da,localX,(void**)&x);
1196:   DMRestoreLocalVector(da, &localX);
1197:   param->ivisc = ivt;
1198:   return(0);
1199: }

1201: /* ------------------------------------------------------------------- */
1204: /* post-processing: compute stress everywhere */
1205: PetscErrorCode StressField(DM da)
1206: /* ------------------------------------------------------------------- */
1207: {
1208:   AppCtx         *user;
1209:   PetscInt       i,j,is,js,im,jm;
1211:   Vec            locVec;
1212:   Field          **x, **y;

1214:   DMGetApplicationContext(da,&user);

1216:   /* Get the fine grid of Xguess and X */
1217:   DMDAGetCorners(da,&is,&js,PETSC_NULL,&im,&jm,PETSC_NULL);
1218:   DMDAVecGetArray(da,user->Xguess,(void**)&x);

1220:   DMGetLocalVector(da, &locVec);
1221:   DMGlobalToLocalBegin(da, user->x, INSERT_VALUES, locVec);
1222:   DMGlobalToLocalEnd(da, user->x, INSERT_VALUES, locVec);
1223:   DMDAVecGetArray(da,locVec,(void**)&y);

1225:   /* Compute stress on the corner points */
1226:   for (j=js; j<js+jm; j++) {
1227:      for (i=is; i<is+im; i++) {
1228: 
1229:         x[j][i].u = ShearStress(y,i,j,CELL_CENTER,user);
1230:         x[j][i].w = ShearStress(y,i,j,CELL_CORNER,user);
1231:         x[j][i].p = XNormalStress(y,i,j,CELL_CENTER,user);
1232:         x[j][i].T = ZNormalStress(y,i,j,CELL_CENTER,user);
1233:     }
1234:   }

1236:   /* Restore the fine grid of Xguess and X */
1237:   DMDAVecRestoreArray(da,user->Xguess,(void**)&x);
1238:   DMDAVecRestoreArray(da,locVec,(void**)&y);
1239:   DMRestoreLocalVector(da, &locVec);
1240:   return 0;
1241: }

1243: /*=====================================================================
1244:   UTILITY FUNCTIONS 
1245:   =====================================================================*/

1247: /*---------------------------------------------------------------------*/
1250: /* returns the velocity of the subducting slab and handles fault nodes 
1251:    for BC */
1252: PETSC_STATIC_INLINE PassiveScalar SlabVel(char c, PetscInt i, PetscInt j, AppCtx *user)
1253: /*---------------------------------------------------------------------*/
1254: {
1255:   Parameter     *param = user->param;
1256:   GridInfo      *grid  = user->grid;

1258:   if (c=='U' || c=='u') {
1259:     if (i<j-1) {
1260:       return param->cb;
1261:     } else if (j<=grid->jfault) {
1262:       return 0.0;
1263:     } else
1264:       return param->cb;

1266:   } else {
1267:     if (i<j) {
1268:       return param->sb;
1269:     } else if (j<=grid->jfault) {
1270:       return 0.0;
1271:     } else
1272:       return param->sb;
1273:   }
1274: }

1276: /*---------------------------------------------------------------------*/
1279: /*  solution to diffusive half-space cooling model for BC */
1280: PETSC_STATIC_INLINE PassiveScalar PlateModel(PetscInt j, PetscInt plate, AppCtx *user)
1281: /*---------------------------------------------------------------------*/
1282: {
1283:   Parameter     *param = user->param;
1284:   PassiveScalar z;
1285:   if (plate==PLATE_LID)
1286:     z = (j-0.5)*user->grid->dz;
1287:   else /* PLATE_SLAB */
1288:     z = (j-0.5)*user->grid->dz*param->cb;
1289: #if defined (PETSC_HAVE_ERF)
1290:   return erf(z*param->L/2.0/param->skt);
1291: #else
1292:   SETERRQ(PETSC_COMM_SELF,1,"erf() not available on this machine");
1293: #endif
1294: }


1297: /* ------------------------------------------------------------------- */
1300: /*  utility function */
1301: PetscBool  OptionsHasName(const char pre[],const char name[])
1302: /* ------------------------------------------------------------------- */
1303: {
1304:   PetscBool      retval;
1306:   PetscOptionsHasName(pre,name,&retval);CHKERRABORT(PETSC_COMM_WORLD,ierr);
1307:   return retval;
1308: }

1310: /*=====================================================================
1311:   INTERACTIVE SIGNAL HANDLING 
1312:   =====================================================================*/

1314: /* ------------------------------------------------------------------- */
1317: PetscErrorCode SNESConverged_Interactive(SNES snes, PetscInt it,PetscReal xnorm, PetscReal snorm, PetscReal fnorm, SNESConvergedReason *reason, void *ctx)
1318: /* ------------------------------------------------------------------- */
1319: {
1320:   AppCtx        *user = (AppCtx *) ctx;
1321:   Parameter     *param = user->param;
1322:   KSP            ksp;

1326:   if (param->interrupted) {
1327:     param->interrupted = PETSC_FALSE;
1328:     PetscPrintf(PETSC_COMM_WORLD,"USER SIGNAL: exiting SNES solve. \n");
1329:     *reason = SNES_CONVERGED_FNORM_ABS;
1330:     return(0);
1331:   } else if (param->toggle_kspmon) {
1332:     param->toggle_kspmon = PETSC_FALSE;
1333:     SNESGetKSP(snes, &ksp);
1334:     if (param->kspmon) {
1335:       KSPMonitorCancel(ksp);
1336:       param->kspmon = PETSC_FALSE;
1337:       PetscPrintf(PETSC_COMM_WORLD,"USER SIGNAL: deactivating ksp singular value monitor. \n");
1338:     } else {
1339:       KSPMonitorSet(ksp,KSPMonitorSingularValue,PETSC_NULL,PETSC_NULL);
1340:       param->kspmon = PETSC_TRUE;
1341:       PetscPrintf(PETSC_COMM_WORLD,"USER SIGNAL: activating ksp singular value monitor. \n");
1342:     }
1343:   }
1344:   PetscFunctionReturn(SNESDefaultConverged(snes,it,xnorm,snorm,fnorm,reason,ctx));
1345: }

1347: /* ------------------------------------------------------------------- */
1348: #include <signal.h>
1351: PetscErrorCode InteractiveHandler(int signum, void *ctx)
1352: /* ------------------------------------------------------------------- */
1353: {
1354:   AppCtx    *user = (AppCtx *) ctx;
1355:   Parameter *param = user->param;

1357:   if (signum == SIGILL) {
1358:     param->toggle_kspmon = PETSC_TRUE;
1359: #if !defined(PETSC_MISSING_SIGCONT)
1360:   } else if (signum == SIGCONT) {
1361:     param->interrupted = PETSC_TRUE;
1362: #endif
1363: #if !defined(PETSC_MISSING_SIGURG)
1364:   } else if (signum == SIGURG) {
1365:     param->stop_solve = PETSC_TRUE;
1366: #endif
1367:   }
1368:   return 0;
1369: }

1371: /*---------------------------------------------------------------------*/
1374: /*  main call-back function that computes the processor-local piece 
1375:     of the residual */
1376: PetscErrorCode FormFunctionLocal(DMDALocalInfo *info,Field **x,Field **f,void *ptr)
1377: /*---------------------------------------------------------------------*/
1378: {
1379:   AppCtx         *user = (AppCtx*)ptr;
1380:   Parameter      *param = user->param;
1381:   GridInfo       *grid  = user->grid;
1382:   PetscScalar    mag_w, mag_u;
1383:   PetscInt       i,j,mx,mz,ilim,jlim;
1384:   PetscInt       is,ie,js,je,ibound; /* ,ivisc */


1388:   /* Define global and local grid parameters */
1389:   mx   = info->mx;     mz   = info->my;
1390:   ilim = mx-1;         jlim = mz-1;
1391:   is   = info->xs;     ie   = info->xs+info->xm;
1392:   js   = info->ys;     je   = info->ys+info->ym;

1394:   /* Define geometric and numeric parameters */
1395:   /* ivisc = param->ivisc; */     ibound = param->ibound;

1397:   for (j=js; j<je; j++) {
1398:     for (i=is; i<ie; i++) {

1400:       /************* X-MOMENTUM/VELOCITY *************/
1401:       if (i<j) {
1402:           f[j][i].u = x[j][i].u - SlabVel('U',i,j,user);

1404:       } else if (j<=grid->jlid || (j<grid->corner+grid->inose && i<grid->corner+grid->inose)) {
1405:         /* in the lithospheric lid */
1406:         f[j][i].u = x[j][i].u - 0.0;

1408:       } else if (i==ilim) {
1409:         /* on the right side boundary */
1410:         if (ibound==BC_ANALYTIC) {
1411:           f[j][i].u = x[j][i].u - HorizVelocity(i,j,user);
1412:         } else {
1413:           f[j][i].u = XNormalStress(x,i,j,CELL_CENTER,user) - EPS_ZERO;
1414:         }

1416:       } else if (j==jlim) {
1417:         /* on the bottom boundary */
1418:         if (ibound==BC_ANALYTIC) {
1419:           f[j][i].u = x[j][i].u - HorizVelocity(i,j,user);
1420:         } else if (ibound==BC_NOSTRESS) {
1421:           f[j][i].u = XMomentumResidual(x,i,j,user);
1422:         } else {
1423:           /* experimental boundary condition */
1424:         }

1426:       } else {
1427:         /* in the mantle wedge */
1428:         f[j][i].u = XMomentumResidual(x,i,j,user);
1429:       }
1430: 
1431:       /************* Z-MOMENTUM/VELOCITY *************/
1432:       if (i<=j) {
1433:         f[j][i].w = x[j][i].w - SlabVel('W',i,j,user);

1435:       } else if (j<=grid->jlid || (j<grid->corner+grid->inose && i<grid->corner+grid->inose)) {
1436:         /* in the lithospheric lid */
1437:         f[j][i].w = x[j][i].w - 0.0;

1439:       } else if (j==jlim) {
1440:         /* on the bottom boundary */
1441:         if (ibound==BC_ANALYTIC) {
1442:           f[j][i].w = x[j][i].w - VertVelocity(i,j,user);
1443:         } else {
1444:           f[j][i].w = ZNormalStress(x,i,j,CELL_CENTER,user) - EPS_ZERO;
1445:         }

1447:       } else if (i==ilim) {
1448:         /* on the right side boundary */
1449:         if (ibound==BC_ANALYTIC) {
1450:           f[j][i].w = x[j][i].w - VertVelocity(i,j,user);
1451:         } else if (ibound==BC_NOSTRESS) {
1452:           f[j][i].w = ZMomentumResidual(x,i,j,user);
1453:         } else {
1454:           /* experimental boundary condition */
1455:         }

1457:       } else {
1458:         /* in the mantle wedge */
1459:         f[j][i].w =  ZMomentumResidual(x,i,j,user);
1460:       }

1462:       /************* CONTINUITY/PRESSURE *************/
1463:       if (i<j || j<=grid->jlid || (j<grid->corner+grid->inose && i<grid->corner+grid->inose)) {
1464:         /* in the lid or slab */
1465:         f[j][i].p = x[j][i].p;
1466: 
1467:       } else if ((i==ilim || j==jlim) && ibound==BC_ANALYTIC) {
1468:         /* on an analytic boundary */
1469:         f[j][i].p = x[j][i].p - Pressure(i,j,user);

1471:       } else {
1472:         /* in the mantle wedge */
1473:         f[j][i].p = ContinuityResidual(x,i,j,user);
1474:       }

1476:       /************* TEMPERATURE *************/
1477:       if (j==0) {
1478:         /* on the surface */
1479:         f[j][i].T = x[j][i].T + x[j+1][i].T + PetscMax(PetscRealPart(x[j][i].T),0.0);

1481:       } else if (i==0) {
1482:         /* slab inflow boundary */
1483:         f[j][i].T = x[j][i].T - PlateModel(j,PLATE_SLAB,user);

1485:       } else if (i==ilim) {
1486:         /* right side boundary */
1487:         mag_u = 1.0 - pow( (1.0-PetscMax(PetscMin(PetscRealPart(x[j][i-1].u)/param->cb,1.0),0.0)), 5.0 );
1488:         f[j][i].T = x[j][i].T - mag_u*x[j-1][i-1].T - (1.0-mag_u)*PlateModel(j,PLATE_LID,user);

1490:       } else if (j==jlim) {
1491:         /* bottom boundary */
1492:         mag_w = 1.0 - pow( (1.0-PetscMax(PetscMin(PetscRealPart(x[j-1][i].w)/param->sb,1.0),0.0)), 5.0 );
1493:         f[j][i].T = x[j][i].T - mag_w*x[j-1][i-1].T - (1.0-mag_w);

1495:       } else {
1496:         /* in the mantle wedge */
1497:         f[j][i].T = EnergyResidual(x,i,j,user);
1498:       }
1499:     }
1500:   }
1501:   return(0);
1502: }