xref: /petsc/src/dm/tests/ex30.c (revision 030f984af8d8bb4c203755d35bded3c05b3d83ce)
1 static char help[] = "Tests DMSLICED operations\n\n";
2 
3 #include <petscdmsliced.h>
4 
5 int main(int argc,char *argv[])
6 {
7   char           mat_type[256] = MATAIJ; /* default matrix type */
8   PetscErrorCode ierr;
9   MPI_Comm       comm;
10   PetscMPIInt    rank,size;
11   DM             slice;
12   PetscInt       i,bs=1,N=5,n,m,rstart,ghosts[2],*d_nnz,*o_nnz,dfill[4]={1,0,0,1},ofill[4]={1,1,1,1};
13   PetscReal      alpha   =1,K=1,rho0=1,u0=0,sigma=0.2;
14   PetscBool      useblock=PETSC_TRUE;
15   PetscScalar    *xx;
16   Mat            A;
17   Vec            x,b,lf;
18 
19   ierr = PetscInitialize(&argc,&argv,0,help);if (ierr) return ierr;
20   comm = PETSC_COMM_WORLD;
21   ierr = MPI_Comm_size(comm,&size);CHKERRMPI(ierr);
22   ierr = MPI_Comm_rank(comm,&rank);CHKERRMPI(ierr);
23 
24   ierr = PetscOptionsBegin(comm,0,"Options for DMSliced test",0);CHKERRQ(ierr);
25   {
26     ierr = PetscOptionsInt("-n","Global number of nodes","",N,&N,NULL);CHKERRQ(ierr);
27     ierr = PetscOptionsInt("-bs","Block size (1 or 2)","",bs,&bs,NULL);CHKERRQ(ierr);
28     if (bs != 1) {
29       if (bs != 2) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Block size must be 1 or 2");
30       ierr = PetscOptionsReal("-alpha","Inverse time step for wave operator","",alpha,&alpha,NULL);CHKERRQ(ierr);
31       ierr = PetscOptionsReal("-K","Bulk modulus of compressibility","",K,&K,NULL);CHKERRQ(ierr);
32       ierr = PetscOptionsReal("-rho0","Reference density","",rho0,&rho0,NULL);CHKERRQ(ierr);
33       ierr = PetscOptionsReal("-u0","Reference velocity","",u0,&u0,NULL);CHKERRQ(ierr);
34       ierr = PetscOptionsReal("-sigma","Width of Gaussian density perturbation","",sigma,&sigma,NULL);CHKERRQ(ierr);
35       ierr = PetscOptionsBool("-block","Use block matrix assembly","",useblock,&useblock,NULL);CHKERRQ(ierr);
36     }
37     ierr = PetscOptionsString("-sliced_mat_type","Matrix type to use (aij or baij)","",mat_type,mat_type,sizeof(mat_type),NULL);CHKERRQ(ierr);
38   }
39   ierr = PetscOptionsEnd();CHKERRQ(ierr);
40 
41   /* Split ownership, set up periodic grid in 1D */
42   n         = PETSC_DECIDE;
43   ierr      = PetscSplitOwnership(comm,&n,&N);CHKERRQ(ierr);
44   rstart    = 0;
45   ierr      = MPI_Scan(&n,&rstart,1,MPIU_INT,MPI_SUM,comm);CHKERRMPI(ierr);
46   rstart   -= n;
47   ghosts[0] = (N+rstart-1)%N;
48   ghosts[1] = (rstart+n)%N;
49 
50   ierr = PetscMalloc2(n,&d_nnz,n,&o_nnz);CHKERRQ(ierr);
51   for (i=0; i<n; i++) {
52     if (size > 1 && (i==0 || i==n-1)) {
53       d_nnz[i] = 2;
54       o_nnz[i] = 1;
55     } else {
56       d_nnz[i] = 3;
57       o_nnz[i] = 0;
58     }
59   }
60   ierr = DMSlicedCreate(comm,bs,n,2,ghosts,d_nnz,o_nnz,&slice);CHKERRQ(ierr); /* Currently does not copy X_nnz so we can't free them until after DMSlicedGetMatrix */
61 
62   if (!useblock) {ierr = DMSlicedSetBlockFills(slice,dfill,ofill);CHKERRQ(ierr);} /* Irrelevant for baij formats */
63   ierr = DMSetMatType(slice,mat_type);CHKERRQ(ierr);
64   ierr = DMCreateMatrix(slice,&A);CHKERRQ(ierr);
65   ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
66   ierr = MatSetOption(A,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
67 
68   ierr = DMCreateGlobalVector(slice,&x);CHKERRQ(ierr);
69   ierr = VecDuplicate(x,&b);CHKERRQ(ierr);
70 
71   ierr = VecGhostGetLocalForm(x,&lf);CHKERRQ(ierr);
72   ierr = VecGetSize(lf,&m);CHKERRQ(ierr);
73   if (m != (n+2)*bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"size of local form %D, expected %D",m,(n+2)*bs);
74   ierr = VecGetArray(lf,&xx);CHKERRQ(ierr);
75   for (i=0; i<n; i++) {
76     PetscInt        row[2],col[9],im,ip;
77     PetscScalar     v[12];
78     const PetscReal xref = 2.0*(rstart+i)/N - 1; /* [-1,1] */
79     const PetscReal h    = 1.0/N;                /* grid spacing */
80     im = (i==0) ? n : i-1;
81     ip = (i==n-1) ? n+1 : i+1;
82     switch (bs) {
83     case 1:                     /* Laplacian with periodic boundaries */
84       col[0] = im;         col[1] = i;        col[2] = ip;
85       v[0]   = -h;           v[1] = 2*h;        v[2] = -h;
86       ierr   = MatSetValuesLocal(A,1,&i,3,col,v,INSERT_VALUES);CHKERRQ(ierr);
87       xx[i]  = PetscSinReal(xref*PETSC_PI);
88       break;
89     case 2:                     /* Linear acoustic wave operator in variables [rho, u], central differences, periodic, timestep 1/alpha */
90       v[0] = -0.5*u0;   v[1] = -0.5*K;      v[2] = alpha; v[3] = 0;       v[4] = 0.5*u0;    v[5] = 0.5*K;
91       v[6] = -0.5/rho0; v[7] = -0.5*u0;     v[8] = 0;     v[9] = alpha;   v[10] = 0.5/rho0; v[11] = 0.5*u0;
92       if (useblock) {
93         row[0] = i; col[0] = im; col[1] = i; col[2] = ip;
94         ierr   = MatSetValuesBlockedLocal(A,1,row,3,col,v,INSERT_VALUES);CHKERRQ(ierr);
95       } else {
96         row[0] = 2*i; row[1] = 2*i+1;
97         col[0] = 2*im; col[1] = 2*im+1; col[2] = 2*i; col[3] = 2*ip; col[4] = 2*ip+1;
98         v[3]   = v[4]; v[4] = v[5];                                                     /* pack values in first row */
99         ierr   = MatSetValuesLocal(A,1,row,5,col,v,INSERT_VALUES);CHKERRQ(ierr);
100         col[2] = 2*i+1;
101         v[8]   = v[9]; v[9] = v[10]; v[10] = v[11];                                     /* pack values in second row */
102         ierr   = MatSetValuesLocal(A,1,row+1,5,col,v+6,INSERT_VALUES);CHKERRQ(ierr);
103       }
104       /* Set current state (gaussian density perturbation) */
105       xx[2*i]   = 0.2*PetscExpReal(-PetscSqr(xref)/(2*PetscSqr(sigma)));
106       xx[2*i+1] = 0;
107       break;
108     default: SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"not implemented for block size %D",bs);
109     }
110   }
111   ierr = VecRestoreArray(lf,&xx);CHKERRQ(ierr);
112   ierr = VecGhostRestoreLocalForm(x,&lf);CHKERRQ(ierr);
113   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
114   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
115 
116   ierr = MatMult(A,x,b);CHKERRQ(ierr);
117   ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
118   ierr = VecView(x,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
119   ierr = VecView(b,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
120 
121   /* Update the ghosted values, view the result on rank 0. */
122   ierr = VecGhostUpdateBegin(b,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
123   ierr = VecGhostUpdateEnd(b,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
124   if (!rank) {
125     ierr = VecGhostGetLocalForm(b,&lf);CHKERRQ(ierr);
126     ierr = PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_SELF,"Local form of b on rank 0, last two nodes are ghost nodes\n");CHKERRQ(ierr);
127     ierr = VecView(lf,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
128     ierr = VecGhostRestoreLocalForm(b,&lf);CHKERRQ(ierr);
129   }
130 
131   ierr = DMDestroy(&slice);CHKERRQ(ierr);
132   ierr = VecDestroy(&x);CHKERRQ(ierr);
133   ierr = VecDestroy(&b);CHKERRQ(ierr);
134   ierr = MatDestroy(&A);CHKERRQ(ierr);
135   ierr = PetscFinalize();
136   return ierr;
137 }
138 
139 /*TEST
140 
141    test:
142       nsize: 2
143       args: -bs 2 -block 0 -sliced_mat_type baij -alpha 10 -u0 0.1
144 
145    test:
146       suffix: 2
147       nsize: 2
148       args: -bs 2 -block 1 -sliced_mat_type aij -alpha 10 -u0 0.1
149 
150    test:
151       suffix: 3
152       nsize: 2
153       args: -bs 2 -block 0 -sliced_mat_type aij -alpha 10 -u0 0.1
154 
155 TEST*/
156