Actual source code: ex4.c

  1: 
  2: static char help[] = "Tests various 2-dimensional DA routines.\n\n";

 4:  #include petscda.h

  8: int main(int argc,char **argv)
  9: {
 10:   PetscMPIInt    rank;
 12:   PetscInt       M = 10,N = 8,m = PETSC_DECIDE;
 13:   PetscInt       s=2,w=2,n = PETSC_DECIDE,nloc,l,i,j,kk;
 14:   PetscInt       Xs,Xm,Ys,Ym,iloc,*iglobal,*ltog;
 15:   PetscInt       *lx = PETSC_NULL,*ly = PETSC_NULL;
 16:   PetscTruth     testorder = PETSC_FALSE,flg;
 17:   DAPeriodicType wrap = DA_NONPERIODIC;
 18:   DA             da;
 19:   PetscViewer    viewer;
 20:   Vec            local,global;
 21:   PetscScalar    value;
 22:   DAStencilType  st = DA_STENCIL_BOX;
 23:   AO             ao;
 24: 
 25:   PetscInitialize(&argc,&argv,(char*)0,help);
 26:   PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"",300,0,400,400,&viewer);
 27: 
 28:   /* Readoptions */
 29:   PetscOptionsGetInt(PETSC_NULL,"-M",&M,PETSC_NULL);
 30:   PetscOptionsGetInt(PETSC_NULL,"-N",&N,PETSC_NULL);
 31:   PetscOptionsGetInt(PETSC_NULL,"-m",&m,PETSC_NULL);
 32:   PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);
 33:   PetscOptionsGetInt(PETSC_NULL,"-s",&s,PETSC_NULL);
 34:   PetscOptionsGetInt(PETSC_NULL,"-w",&w,PETSC_NULL);
 35:   flg  = PETSC_FALSE;
 36:   PetscOptionsGetTruth(PETSC_NULL,"-xwrap",&flg,PETSC_NULL); if (flg)  wrap = DA_XPERIODIC;
 37:   flg  = PETSC_FALSE;
 38:   PetscOptionsGetTruth(PETSC_NULL,"-ywrap",&flg,PETSC_NULL); if (flg)  wrap = DA_YPERIODIC;
 39:   flg  = PETSC_FALSE;
 40:   PetscOptionsGetTruth(PETSC_NULL,"-xywrap",&flg,PETSC_NULL); if (flg) wrap = DA_XYPERIODIC;
 41:   flg  = PETSC_FALSE;
 42:   PetscOptionsGetTruth(PETSC_NULL,"-star",&flg,PETSC_NULL); if (flg)   st = DA_STENCIL_STAR;
 43:   flg  = PETSC_FALSE;
 44:   PetscOptionsGetTruth(PETSC_NULL,"-testorder",&testorder,PETSC_NULL);
 45:   /*
 46:       Test putting two nodes in x and y on each processor, exact last processor 
 47:       in x and y gets the rest.
 48:   */
 49:   flg  = PETSC_FALSE;
 50:   PetscOptionsGetTruth(PETSC_NULL,"-distribute",&flg,PETSC_NULL);
 51:   if (flg) {
 52:     if (m == PETSC_DECIDE) SETERRQ(1,"Must set -m option with -distribute option");
 53:     PetscMalloc(m*sizeof(PetscInt),&lx);
 54:     for (i=0; i<m-1; i++) { lx[i] = 4;}
 55:     lx[m-1] = M - 4*(m-1);
 56:     if (n == PETSC_DECIDE) SETERRQ(1,"Must set -n option with -distribute option");
 57:     PetscMalloc(n*sizeof(PetscInt),&ly);
 58:     for (i=0; i<n-1; i++) { ly[i] = 2;}
 59:     ly[n-1] = N - 2*(n-1);
 60:   }


 63:   /* Create distributed array and get vectors */
 64:   DACreate2d(PETSC_COMM_WORLD,wrap,st,M,N,m,n,w,s,lx,ly,&da);
 65:   if (lx) {
 66:     PetscFree(lx);
 67:     PetscFree(ly);
 68:   }

 70:   DAView(da,viewer);
 71:   DACreateGlobalVector(da,&global);
 72:   DACreateLocalVector(da,&local);

 74:   /* Set global vector; send ghost points to local vectors */
 75:   value = 1;
 76:   VecSet(global,value);
 77:   DAGlobalToLocalBegin(da,global,INSERT_VALUES,local);
 78:   DAGlobalToLocalEnd(da,global,INSERT_VALUES,local);

 80:   /* Scale local vectors according to processor rank; pass to global vector */
 81:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 82:   value = rank;
 83:   VecScale(local,value);
 84:   DALocalToGlobal(da,local,INSERT_VALUES,global);

 86:   if (!testorder) { /* turn off printing when testing ordering mappings */
 87:     PetscPrintf (PETSC_COMM_WORLD,"\nGlobal Vectors:\n");
 88:     PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_NATIVE);
 89:     VecView(global,PETSC_VIEWER_STDOUT_WORLD);
 90:     PetscPrintf (PETSC_COMM_WORLD,"\n\n");
 91:   }

 93:   /* Send ghost points to local vectors */
 94:   DAGlobalToLocalBegin(da,global,INSERT_VALUES,local);
 95:   DAGlobalToLocalEnd(da,global,INSERT_VALUES,local);

 97:   flg  = PETSC_FALSE;
 98:   PetscOptionsGetTruth(PETSC_NULL,"-local_print",&flg,PETSC_NULL);
 99:   if (flg) {
100:     PetscViewer sviewer;
101:     PetscSynchronizedPrintf(PETSC_COMM_WORLD,"\nLocal Vector: processor %d\n",rank);
102:     PetscViewerGetSingleton(PETSC_VIEWER_STDOUT_WORLD,&sviewer);
103:     VecView(local,sviewer);
104:     PetscViewerRestoreSingleton(PETSC_VIEWER_STDOUT_WORLD,&sviewer);
105:   }

107:   /* Tests mappings betweeen application/PETSc orderings */
108:   if (testorder) {
109:     DAGetGhostCorners(da,&Xs,&Ys,PETSC_NULL,&Xm,&Ym,PETSC_NULL);
110:     DAGetGlobalIndices(da,&nloc,&ltog);
111:     DAGetAO(da,&ao);
112:     PetscMalloc(nloc*sizeof(PetscInt),&iglobal);

114:     /* Set iglobal to be global indices for each processor's local and ghost nodes,
115:        using the DA ordering of grid points */
116:     kk = 0;
117:     for (j=Ys; j<Ys+Ym; j++) {
118:       for (i=Xs; i<Xs+Xm; i++) {
119:         iloc = w*((j-Ys)*Xm + i-Xs);
120:         for (l=0; l<w; l++) {
121:           iglobal[kk++] = ltog[iloc+l];
122:         }
123:       }
124:     }

126:     /* Map this to the application ordering (which for DAs is just the natural ordering
127:        that would be used for 1 processor, numbering most rapidly by x, then y) */
128:     AOPetscToApplication(ao,nloc,iglobal);

130:     /* Then map the application ordering back to the PETSc DA ordering */
131:     AOApplicationToPetsc(ao,nloc,iglobal);

133:     /* Verify the mappings */
134:     kk=0;
135:     for (j=Ys; j<Ys+Ym; j++) {
136:       for (i=Xs; i<Xs+Xm; i++) {
137:         iloc = w*((j-Ys)*Xm + i-Xs);
138:         for (l=0; l<w; l++) {
139:           if (iglobal[kk] != ltog[iloc+l]) {
140:             PetscFPrintf(PETSC_COMM_SELF,stdout,"[%d] Problem with mapping: j=%D, i=%D, l=%D, petsc1=%D, petsc2=%D\n",
141:                                 rank,j,i,l,ltog[iloc+l],iglobal[kk]);}
142:           kk++;
143:         }
144:       }
145:     }
146:     PetscFree(iglobal);
147:   }

149:   /* Free memory */
150:   PetscViewerDestroy(viewer);
151:   VecDestroy(local);
152:   VecDestroy(global);
153:   DADestroy(da);

155:   PetscFinalize();
156:   return 0;
157: }