xref: /petsc/src/snes/tests/ex69.c (revision 2fa40bb9206b96114faa7cb222621ec184d31cd2) !
1 
2 static char help[] = "Tests recovery from domain errors in MatMult() and PCApply()\n\n";
3 
4 /*
5       See src/ksp/ksp/tutorials/ex19.c from which this was copied
6 */
7 
8 #include <petscsnes.h>
9 #include <petscdm.h>
10 #include <petscdmda.h>
11 
12 /*
13    User-defined routines and data structures
14 */
15 typedef struct {
16   PetscScalar u,v,omega,temp;
17 } Field;
18 
19 PetscErrorCode FormFunctionLocal(DMDALocalInfo*,Field**,Field**,void*);
20 
21 typedef struct {
22   PetscReal   lidvelocity,prandtl,grashof;  /* physical parameters */
23   PetscBool   draw_contours;                /* flag - 1 indicates drawing contours */
24   PetscBool   errorindomain;
25   PetscBool   errorindomainmf;
26   SNES        snes;
27 } AppCtx;
28 
29 typedef struct {
30   Mat Jmf;
31 } MatShellCtx;
32 
33 extern PetscErrorCode FormInitialGuess(AppCtx*,DM,Vec);
34 extern PetscErrorCode MatMult_MyShell(Mat,Vec,Vec);
35 extern PetscErrorCode MatAssemblyEnd_MyShell(Mat,MatAssemblyType);
36 extern PetscErrorCode PCApply_MyShell(PC,Vec,Vec);
37 extern PetscErrorCode SNESComputeJacobian_MyShell(SNES,Vec,Mat,Mat,void*);
38 
39 int main(int argc,char **argv)
40 {
41   AppCtx         user;                /* user-defined work context */
42   PetscInt       mx,my;
43   PetscErrorCode ierr;
44   MPI_Comm       comm;
45   DM             da;
46   Vec            x;
47   Mat            J = NULL,Jmf = NULL;
48   MatShellCtx    matshellctx;
49   PetscInt       mlocal,nlocal;
50   PC             pc;
51   KSP            ksp;
52   PetscBool      errorinmatmult = PETSC_FALSE,errorinpcapply = PETSC_FALSE,errorinpcsetup = PETSC_FALSE;
53 
54   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
55   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_matmult",&errorinmatmult,NULL);CHKERRQ(ierr);
56   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_pcapply",&errorinpcapply,NULL);CHKERRQ(ierr);
57   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_pcsetup",&errorinpcsetup,NULL);CHKERRQ(ierr);
58   user.errorindomain = PETSC_FALSE;
59   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_domain",&user.errorindomain,NULL);CHKERRQ(ierr);
60   user.errorindomainmf = PETSC_FALSE;
61   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_domainmf",&user.errorindomainmf,NULL);CHKERRQ(ierr);
62 
63   comm = PETSC_COMM_WORLD;
64   ierr = SNESCreate(comm,&user.snes);CHKERRQ(ierr);
65 
66   /*
67       Create distributed array object to manage parallel grid and vectors
68       for principal unknowns (x) and governing residuals (f)
69   */
70   ierr = DMDACreate2d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,4,4,PETSC_DECIDE,PETSC_DECIDE,4,1,0,0,&da);CHKERRQ(ierr);
71   ierr = DMSetFromOptions(da);CHKERRQ(ierr);
72   ierr = DMSetUp(da);CHKERRQ(ierr);
73   ierr = SNESSetDM(user.snes,da);CHKERRQ(ierr);
74 
75   ierr = DMDAGetInfo(da,0,&mx,&my,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,
76                      PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE);CHKERRQ(ierr);
77   /*
78      Problem parameters (velocity of lid, prandtl, and grashof numbers)
79   */
80   user.lidvelocity = 1.0/(mx*my);
81   user.prandtl     = 1.0;
82   user.grashof     = 1.0;
83 
84   ierr = PetscOptionsGetReal(NULL,NULL,"-lidvelocity",&user.lidvelocity,NULL);CHKERRQ(ierr);
85   ierr = PetscOptionsGetReal(NULL,NULL,"-prandtl",&user.prandtl,NULL);CHKERRQ(ierr);
86   ierr = PetscOptionsGetReal(NULL,NULL,"-grashof",&user.grashof,NULL);CHKERRQ(ierr);
87   ierr = PetscOptionsHasName(NULL,NULL,"-contours",&user.draw_contours);CHKERRQ(ierr);
88 
89   ierr = DMDASetFieldName(da,0,"x_velocity");CHKERRQ(ierr);
90   ierr = DMDASetFieldName(da,1,"y_velocity");CHKERRQ(ierr);
91   ierr = DMDASetFieldName(da,2,"Omega");CHKERRQ(ierr);
92   ierr = DMDASetFieldName(da,3,"temperature");CHKERRQ(ierr);
93 
94   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
95      Create user context, set problem data, create vector data structures.
96      Also, compute the initial guess.
97      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
98 
99   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
100      Create nonlinear solver context
101 
102      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
103   ierr = DMSetApplicationContext(da,&user);CHKERRQ(ierr);
104   ierr = DMDASNESSetFunctionLocal(da,INSERT_VALUES,(PetscErrorCode (*)(DMDALocalInfo*,void*,void*,void*))FormFunctionLocal,&user);CHKERRQ(ierr);
105 
106   if (errorinmatmult) {
107     ierr = MatCreateSNESMF(user.snes,&Jmf);CHKERRQ(ierr);
108     ierr = MatSetFromOptions(Jmf);CHKERRQ(ierr);
109     ierr = MatGetLocalSize(Jmf,&mlocal,&nlocal);CHKERRQ(ierr);
110     matshellctx.Jmf = Jmf;
111     ierr = MatCreateShell(PetscObjectComm((PetscObject)Jmf),mlocal,nlocal,PETSC_DECIDE,PETSC_DECIDE,&matshellctx,&J);CHKERRQ(ierr);
112     ierr = MatShellSetOperation(J,MATOP_MULT,(void (*)(void))MatMult_MyShell);CHKERRQ(ierr);
113     ierr = MatShellSetOperation(J,MATOP_ASSEMBLY_END,(void (*)(void))MatAssemblyEnd_MyShell);CHKERRQ(ierr);
114     ierr = SNESSetJacobian(user.snes,J,J,MatMFFDComputeJacobian,NULL);CHKERRQ(ierr);
115   }
116 
117   ierr = SNESSetFromOptions(user.snes);CHKERRQ(ierr);
118   ierr = PetscPrintf(comm,"lid velocity = %g, prandtl # = %g, grashof # = %g\n",(double)user.lidvelocity,(double)user.prandtl,(double)user.grashof);CHKERRQ(ierr);
119 
120   if (errorinpcapply) {
121     ierr = SNESGetKSP(user.snes,&ksp);CHKERRQ(ierr);
122     ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
123     ierr = PCSetType(pc,PCSHELL);CHKERRQ(ierr);
124     ierr = PCShellSetApply(pc,PCApply_MyShell);CHKERRQ(ierr);
125   }
126 
127   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
128      Solve the nonlinear system
129      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
130   ierr = DMCreateGlobalVector(da,&x);CHKERRQ(ierr);
131   ierr = FormInitialGuess(&user,da,x);CHKERRQ(ierr);
132 
133   if (errorinpcsetup) {
134     ierr = SNESSetUp(user.snes);CHKERRQ(ierr);
135     ierr = SNESSetJacobian(user.snes,NULL,NULL,SNESComputeJacobian_MyShell,NULL);CHKERRQ(ierr);
136   }
137   ierr = SNESSolve(user.snes,NULL,x);CHKERRQ(ierr);
138 
139   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
140      Free work space.  All PETSc objects should be destroyed when they
141      are no longer needed.
142      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
143   ierr = MatDestroy(&J);CHKERRQ(ierr);
144   ierr = MatDestroy(&Jmf);CHKERRQ(ierr);
145   ierr = VecDestroy(&x);CHKERRQ(ierr);
146   ierr = DMDestroy(&da);CHKERRQ(ierr);
147   ierr = SNESDestroy(&user.snes);CHKERRQ(ierr);
148   ierr = PetscFinalize();
149   return ierr;
150 }
151 
152 /* ------------------------------------------------------------------- */
153 
154 /*
155    FormInitialGuess - Forms initial approximation.
156 
157    Input Parameters:
158    user - user-defined application context
159    X - vector
160 
161    Output Parameter:
162    X - vector
163 */
164 PetscErrorCode FormInitialGuess(AppCtx *user,DM da,Vec X)
165 {
166   PetscInt       i,j,mx,xs,ys,xm,ym;
167   PetscErrorCode ierr;
168   PetscReal      grashof,dx;
169   Field          **x;
170 
171   PetscFunctionBeginUser;
172   grashof = user->grashof;
173 
174   ierr = DMDAGetInfo(da,0,&mx,0,0,0,0,0,0,0,0,0,0,0);CHKERRQ(ierr);
175   dx   = 1.0/(mx-1);
176 
177   /*
178      Get local grid boundaries (for 2-dimensional DMDA):
179        xs, ys   - starting grid indices (no ghost points)
180        xm, ym   - widths of local grid (no ghost points)
181   */
182   ierr = DMDAGetCorners(da,&xs,&ys,NULL,&xm,&ym,NULL);CHKERRQ(ierr);
183 
184   /*
185      Get a pointer to vector data.
186        - For default PETSc vectors, VecGetArray() returns a pointer to
187          the data array.  Otherwise, the routine is implementation dependent.
188        - You MUST call VecRestoreArray() when you no longer need access to
189          the array.
190   */
191   ierr = DMDAVecGetArray(da,X,&x);CHKERRQ(ierr);
192 
193   /*
194      Compute initial guess over the locally owned part of the grid
195      Initial condition is motionless fluid and equilibrium temperature
196   */
197   for (j=ys; j<ys+ym; j++) {
198     for (i=xs; i<xs+xm; i++) {
199       x[j][i].u     = 0.0;
200       x[j][i].v     = 0.0;
201       x[j][i].omega = 0.0;
202       x[j][i].temp  = (grashof>0)*i*dx;
203     }
204   }
205 
206   /*
207      Restore vector
208   */
209   ierr = DMDAVecRestoreArray(da,X,&x);CHKERRQ(ierr);
210   PetscFunctionReturn(0);
211 }
212 
213 PetscErrorCode FormFunctionLocal(DMDALocalInfo *info,Field **x,Field **f,void *ptr)
214 {
215   AppCtx          *user = (AppCtx*)ptr;
216   PetscErrorCode  ierr;
217   PetscInt        xints,xinte,yints,yinte,i,j;
218   PetscReal       hx,hy,dhx,dhy,hxdhy,hydhx;
219   PetscReal       grashof,prandtl,lid;
220   PetscScalar     u,uxx,uyy,vx,vy,avx,avy,vxp,vxm,vyp,vym;
221   static PetscInt fail = 0;
222 
223   PetscFunctionBeginUser;
224   if ((fail++ > 7 && user->errorindomainmf) || (fail++ > 36 && user->errorindomain)) {
225     PetscMPIInt rank;
226     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)user->snes),&rank);CHKERRMPI(ierr);
227     if (rank == 0) {
228       ierr = SNESSetFunctionDomainError(user->snes);CHKERRQ(ierr);
229     }
230   }
231   grashof = user->grashof;
232   prandtl = user->prandtl;
233   lid     = user->lidvelocity;
234 
235   /*
236      Define mesh intervals ratios for uniform grid.
237 
238      Note: FD formulae below are normalized by multiplying through by
239      local volume element (i.e. hx*hy) to obtain coefficients O(1) in two dimensions.
240 
241   */
242   dhx   = (PetscReal)(info->mx-1);  dhy = (PetscReal)(info->my-1);
243   hx    = 1.0/dhx;                   hy = 1.0/dhy;
244   hxdhy = hx*dhy;                 hydhx = hy*dhx;
245 
246   xints = info->xs; xinte = info->xs+info->xm; yints = info->ys; yinte = info->ys+info->ym;
247 
248   /* Test whether we are on the bottom edge of the global array */
249   if (yints == 0) {
250     j     = 0;
251     yints = yints + 1;
252     /* bottom edge */
253     for (i=info->xs; i<info->xs+info->xm; i++) {
254       f[j][i].u     = x[j][i].u;
255       f[j][i].v     = x[j][i].v;
256       f[j][i].omega = x[j][i].omega + (x[j+1][i].u - x[j][i].u)*dhy;
257       f[j][i].temp  = x[j][i].temp-x[j+1][i].temp;
258     }
259   }
260 
261   /* Test whether we are on the top edge of the global array */
262   if (yinte == info->my) {
263     j     = info->my - 1;
264     yinte = yinte - 1;
265     /* top edge */
266     for (i=info->xs; i<info->xs+info->xm; i++) {
267       f[j][i].u     = x[j][i].u - lid;
268       f[j][i].v     = x[j][i].v;
269       f[j][i].omega = x[j][i].omega + (x[j][i].u - x[j-1][i].u)*dhy;
270       f[j][i].temp  = x[j][i].temp-x[j-1][i].temp;
271     }
272   }
273 
274   /* Test whether we are on the left edge of the global array */
275   if (xints == 0) {
276     i     = 0;
277     xints = xints + 1;
278     /* left edge */
279     for (j=info->ys; j<info->ys+info->ym; j++) {
280       f[j][i].u     = x[j][i].u;
281       f[j][i].v     = x[j][i].v;
282       f[j][i].omega = x[j][i].omega - (x[j][i+1].v - x[j][i].v)*dhx;
283       f[j][i].temp  = x[j][i].temp;
284     }
285   }
286 
287   /* Test whether we are on the right edge of the global array */
288   if (xinte == info->mx) {
289     i     = info->mx - 1;
290     xinte = xinte - 1;
291     /* right edge */
292     for (j=info->ys; j<info->ys+info->ym; j++) {
293       f[j][i].u     = x[j][i].u;
294       f[j][i].v     = x[j][i].v;
295       f[j][i].omega = x[j][i].omega - (x[j][i].v - x[j][i-1].v)*dhx;
296       f[j][i].temp  = x[j][i].temp - (PetscReal)(grashof>0);
297     }
298   }
299 
300   /* Compute over the interior points */
301   for (j=yints; j<yinte; j++) {
302     for (i=xints; i<xinte; i++) {
303 
304       /*
305        convective coefficients for upwinding
306       */
307       vx  = x[j][i].u; avx = PetscAbsScalar(vx);
308       vxp = .5*(vx+avx); vxm = .5*(vx-avx);
309       vy  = x[j][i].v; avy = PetscAbsScalar(vy);
310       vyp = .5*(vy+avy); vym = .5*(vy-avy);
311 
312       /* U velocity */
313       u         = x[j][i].u;
314       uxx       = (2.0*u - x[j][i-1].u - x[j][i+1].u)*hydhx;
315       uyy       = (2.0*u - x[j-1][i].u - x[j+1][i].u)*hxdhy;
316       f[j][i].u = uxx + uyy - .5*(x[j+1][i].omega-x[j-1][i].omega)*hx;
317 
318       /* V velocity */
319       u         = x[j][i].v;
320       uxx       = (2.0*u - x[j][i-1].v - x[j][i+1].v)*hydhx;
321       uyy       = (2.0*u - x[j-1][i].v - x[j+1][i].v)*hxdhy;
322       f[j][i].v = uxx + uyy + .5*(x[j][i+1].omega-x[j][i-1].omega)*hy;
323 
324       /* Omega */
325       u             = x[j][i].omega;
326       uxx           = (2.0*u - x[j][i-1].omega - x[j][i+1].omega)*hydhx;
327       uyy           = (2.0*u - x[j-1][i].omega - x[j+1][i].omega)*hxdhy;
328       f[j][i].omega = uxx + uyy + (vxp*(u - x[j][i-1].omega) + vxm*(x[j][i+1].omega - u))*hy +
329                       (vyp*(u - x[j-1][i].omega) + vym*(x[j+1][i].omega - u))*hx -
330                       .5*grashof*(x[j][i+1].temp - x[j][i-1].temp)*hy;
331 
332       /* Temperature */
333       u            = x[j][i].temp;
334       uxx          = (2.0*u - x[j][i-1].temp - x[j][i+1].temp)*hydhx;
335       uyy          = (2.0*u - x[j-1][i].temp - x[j+1][i].temp)*hxdhy;
336       f[j][i].temp =  uxx + uyy  + prandtl*((vxp*(u - x[j][i-1].temp) + vxm*(x[j][i+1].temp - u))*hy +
337                                             (vyp*(u - x[j-1][i].temp) + vym*(x[j+1][i].temp - u))*hx);
338     }
339   }
340 
341   /*
342      Flop count (multiply-adds are counted as 2 operations)
343   */
344   ierr = PetscLogFlops(84.0*info->ym*info->xm);CHKERRQ(ierr);
345   PetscFunctionReturn(0);
346 }
347 
348 PetscErrorCode MatMult_MyShell(Mat A,Vec x,Vec y)
349 {
350   PetscErrorCode  ierr;
351   MatShellCtx     *matshellctx;
352   static PetscInt fail = 0;
353 
354   PetscFunctionBegin;
355   ierr = MatShellGetContext(A,&matshellctx);CHKERRQ(ierr);
356   ierr = MatMult(matshellctx->Jmf,x,y);CHKERRQ(ierr);
357   if (fail++ > 5) {
358     PetscMPIInt rank;
359     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRMPI(ierr);
360     if (rank == 0) {ierr = VecSetInf(y);CHKERRQ(ierr);}
361   }
362   PetscFunctionReturn(0);
363 }
364 
365 PetscErrorCode MatAssemblyEnd_MyShell(Mat A,MatAssemblyType tp)
366 {
367   PetscErrorCode ierr;
368   MatShellCtx    *matshellctx;
369 
370   PetscFunctionBegin;
371   ierr = MatShellGetContext(A,&matshellctx);CHKERRQ(ierr);
372   ierr = MatAssemblyEnd(matshellctx->Jmf,tp);CHKERRQ(ierr);
373   PetscFunctionReturn(0);
374 }
375 
376 PetscErrorCode PCApply_MyShell(PC pc,Vec x,Vec y)
377 {
378   PetscErrorCode ierr;
379   static PetscInt fail = 0;
380 
381   PetscFunctionBegin;
382   ierr = VecCopy(x,y);CHKERRQ(ierr);
383   if (fail++ > 3) {
384     PetscMPIInt rank;
385     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)pc),&rank);CHKERRMPI(ierr);
386     if (rank == 0) {ierr = VecSetInf(y);CHKERRQ(ierr);}
387   }
388   PetscFunctionReturn(0);
389 }
390 
391 PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES,Vec,Mat,Mat,void*);
392 
393 PetscErrorCode SNESComputeJacobian_MyShell(SNES snes,Vec X,Mat A,Mat B,void *ctx)
394 {
395   static PetscInt fail = 0;
396   PetscErrorCode  ierr;
397 
398   PetscFunctionBegin;
399   ierr = SNESComputeJacobian_DMDA(snes,X,A,B,ctx);CHKERRQ(ierr);
400   if (fail++ > 0) {
401     ierr = MatZeroEntries(A);CHKERRQ(ierr);
402   }
403   PetscFunctionReturn(0);
404 }
405 
406 /*TEST
407 
408    test:
409       args: -snes_converged_reason -ksp_converged_reason
410 
411    test:
412       suffix: 2
413       args: -snes_converged_reason -ksp_converged_reason -error_in_matmult
414 
415    test:
416       suffix: 3
417       args: -snes_converged_reason -ksp_converged_reason -error_in_pcapply
418 
419    test:
420       suffix: 4
421       args: -snes_converged_reason -ksp_converged_reason -error_in_pcsetup
422 
423    test:
424       suffix: 5
425       args: -snes_converged_reason -ksp_converged_reason -error_in_pcsetup -pc_type bjacobi
426 
427    test:
428       suffix: 5_fieldsplit
429       args: -snes_converged_reason -ksp_converged_reason -error_in_pcsetup -pc_type fieldsplit
430       output_file: output/ex69_5.out
431 
432    test:
433       suffix: 6
434       args: -snes_converged_reason -ksp_converged_reason -error_in_domainmf -snes_mf -pc_type none
435 
436    test:
437       suffix: 7
438       args: -snes_converged_reason -ksp_converged_reason -error_in_domain
439 
440    test:
441       suffix: 8
442       args: -snes_converged_reason -ksp_converged_reason -error_in_domain -snes_mf -pc_type none
443 
444 TEST*/
445