Actual source code: ex4.c

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

  4: #include <petscdmda.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:   PetscBool      testorder = PETSC_FALSE,flg;
 17:   DMDABoundaryType bx = DMDA_BOUNDARY_NONE,by= DMDA_BOUNDARY_NONE;
 18:   DM             da;
 19:   PetscViewer    viewer;
 20:   Vec            local,global;
 21:   PetscScalar    value;
 22:   DMDAStencilType  st = DMDA_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,"-NX",&M,PETSC_NULL);
 30:   PetscOptionsGetInt(PETSC_NULL,"-NY",&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);

 36:   flg  = PETSC_FALSE;
 37:   PetscOptionsGetBool(PETSC_NULL,"-xperiodic",&flg,PETSC_NULL); if (flg) bx = DMDA_BOUNDARY_PERIODIC;
 38:   flg  = PETSC_FALSE;
 39:   PetscOptionsGetBool(PETSC_NULL,"-yperiodic",&flg,PETSC_NULL); if (flg) by = DMDA_BOUNDARY_PERIODIC;
 40:   flg  = PETSC_FALSE;
 41:   PetscOptionsGetBool(PETSC_NULL,"-xghosted",&flg,PETSC_NULL); if (flg) bx = DMDA_BOUNDARY_GHOSTED;
 42:   flg  = PETSC_FALSE;
 43:   PetscOptionsGetBool(PETSC_NULL,"-yghosted",&flg,PETSC_NULL); if (flg) by = DMDA_BOUNDARY_GHOSTED;
 44:   flg  = PETSC_FALSE;
 45:   PetscOptionsGetBool(PETSC_NULL,"-star",&flg,PETSC_NULL); if (flg) st = DMDA_STENCIL_STAR;
 46:   flg  = PETSC_FALSE;
 47:   PetscOptionsGetBool(PETSC_NULL,"-box",&flg,PETSC_NULL); if (flg) st = DMDA_STENCIL_BOX;
 48:   flg  = PETSC_FALSE;
 49:   PetscOptionsGetBool(PETSC_NULL,"-testorder",&testorder,PETSC_NULL);
 50:   /*
 51:       Test putting two nodes in x and y on each processor, exact last processor 
 52:       in x and y gets the rest.
 53:   */
 54:   flg  = PETSC_FALSE;
 55:   PetscOptionsGetBool(PETSC_NULL,"-distribute",&flg,PETSC_NULL);
 56:   if (flg) {
 57:     if (m == PETSC_DECIDE) SETERRQ(PETSC_COMM_WORLD,1,"Must set -m option with -distribute option");
 58:     PetscMalloc(m*sizeof(PetscInt),&lx);
 59:     for (i=0; i<m-1; i++) { lx[i] = 4;}
 60:     lx[m-1] = M - 4*(m-1);
 61:     if (n == PETSC_DECIDE) SETERRQ(PETSC_COMM_WORLD,1,"Must set -n option with -distribute option");
 62:     PetscMalloc(n*sizeof(PetscInt),&ly);
 63:     for (i=0; i<n-1; i++) { ly[i] = 2;}
 64:     ly[n-1] = N - 2*(n-1);
 65:   }


 68:   /* Create distributed array and get vectors */
 69:   DMDACreate2d(PETSC_COMM_WORLD,bx,by,st,M,N,m,n,w,s,lx,ly,&da);
 70:   PetscFree(lx);
 71:   PetscFree(ly);

 73:   DMView(da,viewer);
 74:   DMCreateGlobalVector(da,&global);
 75:   DMCreateLocalVector(da,&local);

 77:   /* Set global vector; send ghost points to local vectors */
 78:   value = 1;
 79:   VecSet(global,value);
 80:   DMGlobalToLocalBegin(da,global,INSERT_VALUES,local);
 81:   DMGlobalToLocalEnd(da,global,INSERT_VALUES,local);

 83:   /* Scale local vectors according to processor rank; pass to global vector */
 84:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 85:   value = rank;
 86:   VecScale(local,value);
 87:   DMLocalToGlobalBegin(da,local,INSERT_VALUES,global);
 88:   DMLocalToGlobalEnd(da,local,INSERT_VALUES,global);

 90:   if (!testorder) { /* turn off printing when testing ordering mappings */
 91:     PetscPrintf (PETSC_COMM_WORLD,"\nGlobal Vectors:\n");
 92:     VecView(global,PETSC_VIEWER_STDOUT_WORLD);
 93:     PetscPrintf (PETSC_COMM_WORLD,"\n\n");
 94:   }

 96:   /* Send ghost points to local vectors */
 97:   DMGlobalToLocalBegin(da,global,INSERT_VALUES,local);
 98:   DMGlobalToLocalEnd(da,global,INSERT_VALUES,local);

100:   flg  = PETSC_FALSE;
101:   PetscOptionsGetBool(PETSC_NULL,"-local_print",&flg,PETSC_NULL);
102:   if (flg) {
103:     PetscViewer sviewer;
104:     PetscSynchronizedPrintf(PETSC_COMM_WORLD,"\nLocal Vector: processor %d\n",rank);
105:     PetscViewerGetSingleton(PETSC_VIEWER_STDOUT_WORLD,&sviewer);
106:     VecView(local,sviewer);
107:     PetscViewerRestoreSingleton(PETSC_VIEWER_STDOUT_WORLD,&sviewer);
108:   }

110:   /* Tests mappings betweeen application/PETSc orderings */
111:   if (testorder) {
112:     DMDAGetGhostCorners(da,&Xs,&Ys,PETSC_NULL,&Xm,&Ym,PETSC_NULL);
113:     DMDAGetGlobalIndices(da,&nloc,&ltog);
114:     DMDAGetAO(da,&ao);
115:     PetscMalloc(nloc*sizeof(PetscInt),&iglobal);

117:     /* Set iglobal to be global indices for each processor's local and ghost nodes,
118:        using the DMDA ordering of grid points */
119:     kk = 0;
120:     for (j=Ys; j<Ys+Ym; j++) {
121:       for (i=Xs; i<Xs+Xm; i++) {
122:         iloc = w*((j-Ys)*Xm + i-Xs);
123:         for (l=0; l<w; l++) {
124:           iglobal[kk++] = ltog[iloc+l];
125:         }
126:       }
127:     }

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

133:     /* Then map the application ordering back to the PETSc DMDA ordering */
134:     AOApplicationToPetsc(ao,nloc,iglobal);

136:     /* Verify the mappings */
137:     kk=0;
138:     for (j=Ys; j<Ys+Ym; j++) {
139:       for (i=Xs; i<Xs+Xm; i++) {
140:         iloc = w*((j-Ys)*Xm + i-Xs);
141:         for (l=0; l<w; l++) {
142:           if (iglobal[kk] != ltog[iloc+l]) {
143:             PetscFPrintf(PETSC_COMM_SELF,stdout,"[%d] Problem with mapping: j=%D, i=%D, l=%D, petsc1=%D, petsc2=%D\n",
144:                                 rank,j,i,l,ltog[iloc+l],iglobal[kk]);}
145:           kk++;
146:         }
147:       }
148:     }
149:     PetscFree(iglobal);
150:   }

152:   /* Free memory */
153:   PetscViewerDestroy(&viewer);
154:   VecDestroy(&local);
155:   VecDestroy(&global);
156:   DMDestroy(&da);

158:   PetscFinalize();
159:   return 0;
160: }