xref: /petsc/src/mat/tests/ex145.c (revision c20d77252dee0f9c80fc6f8b1a6f948e11175edb)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests LU, Cholesky factorization and MatMatSolve() for an Elemental dense matrix.\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscmat.h>
5c4762a1bSJed Brown 
6c4762a1bSJed Brown int main(int argc,char **argv)
7c4762a1bSJed Brown {
8c4762a1bSJed Brown   Mat            A,F,B,X,C,Aher,G;
9c4762a1bSJed Brown   Vec            b,x,c,d,e;
10c4762a1bSJed Brown   PetscErrorCode ierr;
11c4762a1bSJed Brown   PetscInt       m = 5,n,p,i,j,nrows,ncols;
12c4762a1bSJed Brown   PetscScalar    *v,*barray,rval;
13c4762a1bSJed Brown   PetscReal      norm,tol=1.e-11;
14c4762a1bSJed Brown   PetscMPIInt    size,rank;
15c4762a1bSJed Brown   PetscRandom    rand;
16c4762a1bSJed Brown   const PetscInt *rows,*cols;
17c4762a1bSJed Brown   IS             isrows,iscols;
18c4762a1bSJed Brown   PetscBool      mats_view=PETSC_FALSE;
19c4762a1bSJed Brown   MatFactorInfo  finfo;
20c4762a1bSJed Brown 
21c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&argv,(char*) 0,help);if (ierr) return ierr;
22c4762a1bSJed Brown   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
23c4762a1bSJed Brown   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
24c4762a1bSJed Brown 
25c4762a1bSJed Brown   ierr = PetscRandomCreate(PETSC_COMM_WORLD,&rand);CHKERRQ(ierr);
26c4762a1bSJed Brown   ierr = PetscRandomSetFromOptions(rand);CHKERRQ(ierr);
27c4762a1bSJed Brown 
28c4762a1bSJed Brown   /* Get local dimensions of matrices */
29c4762a1bSJed Brown   ierr = PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);CHKERRQ(ierr);
30c4762a1bSJed Brown   n    = m;
31c4762a1bSJed Brown   ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr);
32c4762a1bSJed Brown   p    = m/2;
33c4762a1bSJed Brown   ierr = PetscOptionsGetInt(NULL,NULL,"-p",&p,NULL);CHKERRQ(ierr);
34c4762a1bSJed Brown   ierr = PetscOptionsHasName(NULL,NULL,"-mats_view",&mats_view);CHKERRQ(ierr);
35c4762a1bSJed Brown 
36c4762a1bSJed Brown   /* Create matrix A */
37c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD," Create Elemental matrix A\n");CHKERRQ(ierr);
38c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
39c4762a1bSJed Brown   ierr = MatSetSizes(A,m,n,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
40c4762a1bSJed Brown   ierr = MatSetType(A,MATELEMENTAL);CHKERRQ(ierr);
41c4762a1bSJed Brown   ierr = MatSetFromOptions(A);CHKERRQ(ierr);
42c4762a1bSJed Brown   ierr = MatSetUp(A);CHKERRQ(ierr);
43c4762a1bSJed Brown   /* Set local matrix entries */
44c4762a1bSJed Brown   ierr = MatGetOwnershipIS(A,&isrows,&iscols);CHKERRQ(ierr);
45c4762a1bSJed Brown   ierr = ISGetLocalSize(isrows,&nrows);CHKERRQ(ierr);
46c4762a1bSJed Brown   ierr = ISGetIndices(isrows,&rows);CHKERRQ(ierr);
47c4762a1bSJed Brown   ierr = ISGetLocalSize(iscols,&ncols);CHKERRQ(ierr);
48c4762a1bSJed Brown   ierr = ISGetIndices(iscols,&cols);CHKERRQ(ierr);
49c4762a1bSJed Brown   ierr = PetscMalloc1(nrows*ncols,&v);CHKERRQ(ierr);
50c4762a1bSJed Brown   for (i=0; i<nrows; i++) {
51c4762a1bSJed Brown     for (j=0; j<ncols; j++) {
52c4762a1bSJed Brown       ierr         = PetscRandomGetValue(rand,&rval);CHKERRQ(ierr);
53c4762a1bSJed Brown       v[i*ncols+j] = rval;
54c4762a1bSJed Brown     }
55c4762a1bSJed Brown   }
56c4762a1bSJed Brown   ierr = MatSetValues(A,nrows,rows,ncols,cols,v,INSERT_VALUES);CHKERRQ(ierr);
57c4762a1bSJed Brown   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
58c4762a1bSJed Brown   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
59c4762a1bSJed Brown   ierr = ISRestoreIndices(isrows,&rows);CHKERRQ(ierr);
60c4762a1bSJed Brown   ierr = ISRestoreIndices(iscols,&cols);CHKERRQ(ierr);
61c4762a1bSJed Brown   ierr = ISDestroy(&isrows);CHKERRQ(ierr);
62c4762a1bSJed Brown   ierr = ISDestroy(&iscols);CHKERRQ(ierr);
63c4762a1bSJed Brown   ierr = PetscFree(v);CHKERRQ(ierr);
64c4762a1bSJed Brown   if (mats_view) {
65c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD, "A: nrows %d, m %d; ncols %d, n %d\n",nrows,m,ncols,n);CHKERRQ(ierr);
66c4762a1bSJed Brown     ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
67c4762a1bSJed Brown   }
68c4762a1bSJed Brown 
69c4762a1bSJed Brown   /* Create rhs matrix B */
70c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD," Create rhs matrix B\n");CHKERRQ(ierr);
71c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&B);CHKERRQ(ierr);
72c4762a1bSJed Brown   ierr = MatSetSizes(B,m,p,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
73c4762a1bSJed Brown   ierr = MatSetType(B,MATELEMENTAL);CHKERRQ(ierr);
74c4762a1bSJed Brown   ierr = MatSetFromOptions(B);CHKERRQ(ierr);
75c4762a1bSJed Brown   ierr = MatSetUp(B);CHKERRQ(ierr);
76c4762a1bSJed Brown   ierr = MatGetOwnershipIS(B,&isrows,&iscols);CHKERRQ(ierr);
77c4762a1bSJed Brown   ierr = ISGetLocalSize(isrows,&nrows);CHKERRQ(ierr);
78c4762a1bSJed Brown   ierr = ISGetIndices(isrows,&rows);CHKERRQ(ierr);
79c4762a1bSJed Brown   ierr = ISGetLocalSize(iscols,&ncols);CHKERRQ(ierr);
80c4762a1bSJed Brown   ierr = ISGetIndices(iscols,&cols);CHKERRQ(ierr);
81c4762a1bSJed Brown   ierr = PetscMalloc1(nrows*ncols,&v);CHKERRQ(ierr);
82c4762a1bSJed Brown   for (i=0; i<nrows; i++) {
83c4762a1bSJed Brown     for (j=0; j<ncols; j++) {
84c4762a1bSJed Brown       ierr         = PetscRandomGetValue(rand,&rval);CHKERRQ(ierr);
85c4762a1bSJed Brown       v[i*ncols+j] = rval;
86c4762a1bSJed Brown     }
87c4762a1bSJed Brown   }
88c4762a1bSJed Brown   ierr = MatSetValues(B,nrows,rows,ncols,cols,v,INSERT_VALUES);CHKERRQ(ierr);
89c4762a1bSJed Brown   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
90c4762a1bSJed Brown   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
91c4762a1bSJed Brown   ierr = ISRestoreIndices(isrows,&rows);CHKERRQ(ierr);
92c4762a1bSJed Brown   ierr = ISRestoreIndices(iscols,&cols);CHKERRQ(ierr);
93c4762a1bSJed Brown   ierr = ISDestroy(&isrows);CHKERRQ(ierr);
94c4762a1bSJed Brown   ierr = ISDestroy(&iscols);CHKERRQ(ierr);
95c4762a1bSJed Brown   ierr = PetscFree(v);CHKERRQ(ierr);
96c4762a1bSJed Brown   if (mats_view) {
97c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD, "B: nrows %d, m %d; ncols %d, p %d\n",nrows,m,ncols,p);CHKERRQ(ierr);
98c4762a1bSJed Brown     ierr = MatView(B,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
99c4762a1bSJed Brown   }
100c4762a1bSJed Brown 
101c4762a1bSJed Brown   /* Create rhs vector b and solution x (same size as b) */
102c4762a1bSJed Brown   ierr = VecCreate(PETSC_COMM_WORLD,&b);CHKERRQ(ierr);
103c4762a1bSJed Brown   ierr = VecSetSizes(b,m,PETSC_DECIDE);CHKERRQ(ierr);
104c4762a1bSJed Brown   ierr = VecSetFromOptions(b);CHKERRQ(ierr);
105c4762a1bSJed Brown   ierr = VecGetArray(b,&barray);CHKERRQ(ierr);
106c4762a1bSJed Brown   for (j=0; j<m; j++) {
107c4762a1bSJed Brown     ierr      = PetscRandomGetValue(rand,&rval);CHKERRQ(ierr);
108c4762a1bSJed Brown     barray[j] = rval;
109c4762a1bSJed Brown   }
110c4762a1bSJed Brown   ierr = VecRestoreArray(b,&barray);CHKERRQ(ierr);
111c4762a1bSJed Brown   ierr = VecAssemblyBegin(b);CHKERRQ(ierr);
112c4762a1bSJed Brown   ierr = VecAssemblyEnd(b);CHKERRQ(ierr);
113c4762a1bSJed Brown   if (mats_view) {
114c4762a1bSJed Brown     ierr = PetscSynchronizedPrintf(PETSC_COMM_WORLD, "[%d] b: m %d\n",rank,m);CHKERRQ(ierr);
115c4762a1bSJed Brown     ierr = PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT);CHKERRQ(ierr);
116c4762a1bSJed Brown     ierr = VecView(b,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
117c4762a1bSJed Brown   }
118c4762a1bSJed Brown   ierr = VecDuplicate(b,&x);CHKERRQ(ierr);
119c4762a1bSJed Brown 
120c4762a1bSJed Brown   /* Create matrix X - same size as B */
121c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD," Create solution matrix X\n");CHKERRQ(ierr);
122c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&X);CHKERRQ(ierr);
123c4762a1bSJed Brown   ierr = MatSetSizes(X,m,p,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
124c4762a1bSJed Brown   ierr = MatSetType(X,MATELEMENTAL);CHKERRQ(ierr);
125c4762a1bSJed Brown   ierr = MatSetFromOptions(X);CHKERRQ(ierr);
126c4762a1bSJed Brown   ierr = MatSetUp(X);CHKERRQ(ierr);
127c4762a1bSJed Brown   ierr = MatAssemblyBegin(X,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
128c4762a1bSJed Brown   ierr = MatAssemblyEnd(X,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
129c4762a1bSJed Brown 
130c4762a1bSJed Brown   /* Cholesky factorization */
131c4762a1bSJed Brown   /*------------------------*/
132c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD," Create Elemental matrix Aher\n");CHKERRQ(ierr);
133c4762a1bSJed Brown   ierr = MatHermitianTranspose(A,MAT_INITIAL_MATRIX,&Aher);CHKERRQ(ierr);
134c4762a1bSJed Brown   ierr = MatAXPY(Aher,1.0,A,SAME_NONZERO_PATTERN);CHKERRQ(ierr); /* Aher = A + A^T */
135c4762a1bSJed Brown   if(!rank) { /* add 100.0 to diagonals of Aher to make it spd */
136c4762a1bSJed Brown 
137c4762a1bSJed Brown     /* TODO: Replace this with a call to El::ShiftDiagonal( A, 100. ),
138c4762a1bSJed Brown              or at least pre-allocate the right amount of space */
139c4762a1bSJed Brown     PetscInt M,N;
140c4762a1bSJed Brown     ierr = MatGetSize(Aher,&M,&N);CHKERRQ(ierr);
141c4762a1bSJed Brown     for (i=0; i<M; i++) {
142c4762a1bSJed Brown       rval = 100.0;
143c4762a1bSJed Brown       ierr = MatSetValues(Aher,1,&i,1,&i,&rval,ADD_VALUES);CHKERRQ(ierr);
144c4762a1bSJed Brown     }
145c4762a1bSJed Brown   }
146c4762a1bSJed Brown   ierr = MatAssemblyBegin(Aher,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
147c4762a1bSJed Brown   ierr = MatAssemblyEnd(Aher,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
148c4762a1bSJed Brown   if (mats_view) {
149c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD, "Aher:\n");CHKERRQ(ierr);
150c4762a1bSJed Brown     ierr = MatView(Aher,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
151c4762a1bSJed Brown   }
152c4762a1bSJed Brown 
153c4762a1bSJed Brown   /* Cholesky factorization */
154c4762a1bSJed Brown   /*------------------------*/
155c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD," Test Cholesky Solver \n");CHKERRQ(ierr);
156c4762a1bSJed Brown   /* In-place Cholesky */
157c4762a1bSJed Brown   /* Create matrix factor G, then copy Aher to G */
158c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&G);CHKERRQ(ierr);
159c4762a1bSJed Brown   ierr = MatSetSizes(G,m,n,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
160c4762a1bSJed Brown   ierr = MatSetType(G,MATELEMENTAL);CHKERRQ(ierr);
161c4762a1bSJed Brown   ierr = MatSetFromOptions(G);CHKERRQ(ierr);
162c4762a1bSJed Brown   ierr = MatSetUp(G);CHKERRQ(ierr);
163c4762a1bSJed Brown   ierr = MatAssemblyBegin(G,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
164c4762a1bSJed Brown   ierr = MatAssemblyEnd(G,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
165c4762a1bSJed Brown   ierr = MatCopy(Aher,G,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
166c4762a1bSJed Brown 
167c4762a1bSJed Brown   /* Only G = U^T * U is implemented for now */
168c4762a1bSJed Brown   ierr = MatCholeskyFactor(G,0,0);CHKERRQ(ierr);
169c4762a1bSJed Brown   if (mats_view) {
170c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD, "Cholesky Factor G:\n");CHKERRQ(ierr);
171c4762a1bSJed Brown     ierr = MatView(G,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
172c4762a1bSJed Brown   }
173c4762a1bSJed Brown 
174c4762a1bSJed Brown   /* Solve U^T * U x = b and U^T * U X = B */
175c4762a1bSJed Brown   ierr = MatSolve(G,b,x);CHKERRQ(ierr);
176c4762a1bSJed Brown   ierr = MatMatSolve(G,B,X);CHKERRQ(ierr);
177c4762a1bSJed Brown   ierr = MatDestroy(&G);CHKERRQ(ierr);
178c4762a1bSJed Brown 
179c4762a1bSJed Brown   /* Out-place Cholesky */
180c4762a1bSJed Brown   ierr = MatGetFactor(Aher,MATSOLVERELEMENTAL,MAT_FACTOR_CHOLESKY,&G);CHKERRQ(ierr);
181c4762a1bSJed Brown   ierr = MatCholeskyFactorSymbolic(G,Aher,0,&finfo);CHKERRQ(ierr);
182c4762a1bSJed Brown   ierr = MatCholeskyFactorNumeric(G,Aher,&finfo);CHKERRQ(ierr);
183c4762a1bSJed Brown   if (mats_view) {
184c4762a1bSJed Brown     ierr = MatView(G,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
185c4762a1bSJed Brown   }
186c4762a1bSJed Brown   ierr = MatSolve(G,b,x);CHKERRQ(ierr);
187c4762a1bSJed Brown   ierr = MatMatSolve(G,B,X);CHKERRQ(ierr);
188c4762a1bSJed Brown   ierr = MatDestroy(&G);CHKERRQ(ierr);
189c4762a1bSJed Brown 
190c4762a1bSJed Brown   /* Check norm(Aher*x - b) */
191c4762a1bSJed Brown   ierr = VecCreate(PETSC_COMM_WORLD,&c);CHKERRQ(ierr);
192c4762a1bSJed Brown   ierr = VecSetSizes(c,m,PETSC_DECIDE);CHKERRQ(ierr);
193c4762a1bSJed Brown   ierr = VecSetFromOptions(c);CHKERRQ(ierr);
194c4762a1bSJed Brown   ierr = MatMult(Aher,x,c);CHKERRQ(ierr);
195c4762a1bSJed Brown   ierr = VecAXPY(c,-1.0,b);CHKERRQ(ierr);
196c4762a1bSJed Brown   ierr = VecNorm(c,NORM_1,&norm);CHKERRQ(ierr);
197c4762a1bSJed Brown   if (norm > tol) {
198c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD,"Warning: |Aher*x - b| for Cholesky %g\n",(double)norm);CHKERRQ(ierr);
199c4762a1bSJed Brown   }
200c4762a1bSJed Brown 
201c4762a1bSJed Brown   /* Check norm(Aher*X - B) */
202c4762a1bSJed Brown   ierr = MatMatMult(Aher,X,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&C);CHKERRQ(ierr);
203c4762a1bSJed Brown   ierr = MatAXPY(C,-1.0,B,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
204c4762a1bSJed Brown   ierr = MatNorm(C,NORM_1,&norm);CHKERRQ(ierr);
205c4762a1bSJed Brown   if (norm > tol) {
206c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD,"Warning: |Aher*X - B| for Cholesky %g\n",(double)norm);CHKERRQ(ierr);
207c4762a1bSJed Brown   }
208c4762a1bSJed Brown 
209c4762a1bSJed Brown   /* LU factorization */
210c4762a1bSJed Brown   /*------------------*/
211c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD," Test LU Solver \n");CHKERRQ(ierr);
212c4762a1bSJed Brown   /* In-place LU */
213c4762a1bSJed Brown   /* Create matrix factor F, then copy A to F */
214c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&F);CHKERRQ(ierr);
215c4762a1bSJed Brown   ierr = MatSetSizes(F,m,n,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
216c4762a1bSJed Brown   ierr = MatSetType(F,MATELEMENTAL);CHKERRQ(ierr);
217c4762a1bSJed Brown   ierr = MatSetFromOptions(F);CHKERRQ(ierr);
218c4762a1bSJed Brown   ierr = MatSetUp(F);CHKERRQ(ierr);
219c4762a1bSJed Brown   ierr = MatAssemblyBegin(F,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
220c4762a1bSJed Brown   ierr = MatAssemblyEnd(F,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
221c4762a1bSJed Brown   ierr = MatCopy(A,F,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
222c4762a1bSJed Brown   /* Create vector d to test MatSolveAdd() */
223c4762a1bSJed Brown   ierr = VecDuplicate(x,&d);CHKERRQ(ierr);
224c4762a1bSJed Brown   ierr = VecCopy(x,d);CHKERRQ(ierr);
225c4762a1bSJed Brown 
226c4762a1bSJed Brown   /* PF=LU or F=LU factorization - perms is ignored by Elemental;
227c4762a1bSJed Brown      set finfo.dtcol !0 or 0 to enable/disable partial pivoting */
228c4762a1bSJed Brown   finfo.dtcol = 0.1;
229c4762a1bSJed Brown   ierr        = MatLUFactor(F,0,0,&finfo);CHKERRQ(ierr);
230c4762a1bSJed Brown 
231c4762a1bSJed Brown   /* Solve LUX = PB or LUX = B */
232c4762a1bSJed Brown   ierr = MatSolveAdd(F,b,d,x);CHKERRQ(ierr);
233c4762a1bSJed Brown   ierr = MatMatSolve(F,B,X);CHKERRQ(ierr);
234c4762a1bSJed Brown   ierr = MatDestroy(&F);CHKERRQ(ierr);
235c4762a1bSJed Brown 
236c4762a1bSJed Brown   /* Check norm(A*X - B) */
237c4762a1bSJed Brown   ierr = VecCreate(PETSC_COMM_WORLD,&e);CHKERRQ(ierr);
238c4762a1bSJed Brown   ierr = VecSetSizes(e,m,PETSC_DECIDE);CHKERRQ(ierr);
239c4762a1bSJed Brown   ierr = VecSetFromOptions(e);CHKERRQ(ierr);
240c4762a1bSJed Brown   ierr = MatMult(A,x,c);CHKERRQ(ierr);
241c4762a1bSJed Brown   ierr = MatMult(A,d,e);CHKERRQ(ierr);
242c4762a1bSJed Brown   ierr = VecAXPY(c,-1.0,e);CHKERRQ(ierr);
243c4762a1bSJed Brown   ierr = VecAXPY(c,-1.0,b);CHKERRQ(ierr);
244c4762a1bSJed Brown   ierr = VecNorm(c,NORM_1,&norm);CHKERRQ(ierr);
245c4762a1bSJed Brown   if (norm > tol) {
246c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD,"Warning: |A*x - b| for LU %g\n",(double)norm);CHKERRQ(ierr);
247c4762a1bSJed Brown   }
248*c20d7725SJed Brown   /* Reuse product C; replace Aher with A */
249*c20d7725SJed Brown   ierr = MatProductReplaceMats(A,NULL,NULL,C);CHKERRQ(ierr);
250c4762a1bSJed Brown   ierr = MatMatMult(A,X,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C);CHKERRQ(ierr);
251c4762a1bSJed Brown   ierr = MatAXPY(C,-1.0,B,SAME_NONZERO_PATTERN);CHKERRQ(ierr);
252c4762a1bSJed Brown   ierr = MatNorm(C,NORM_1,&norm);CHKERRQ(ierr);
253c4762a1bSJed Brown   if (norm > tol) {
254c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_WORLD,"Warning: |A*X - B| for LU %g\n",(double)norm);CHKERRQ(ierr);
255c4762a1bSJed Brown   }
256c4762a1bSJed Brown 
257c4762a1bSJed Brown   /* Out-place LU */
258c4762a1bSJed Brown   ierr = MatGetFactor(A,MATSOLVERELEMENTAL,MAT_FACTOR_LU,&F);CHKERRQ(ierr);
259c4762a1bSJed Brown   ierr = MatLUFactorSymbolic(F,A,0,0,&finfo);CHKERRQ(ierr);
260c4762a1bSJed Brown   ierr = MatLUFactorNumeric(F,A,&finfo);CHKERRQ(ierr);
261c4762a1bSJed Brown   if (mats_view) {
262c4762a1bSJed Brown     ierr = MatView(F,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
263c4762a1bSJed Brown   }
264c4762a1bSJed Brown   ierr = MatSolve(F,b,x);CHKERRQ(ierr);
265c4762a1bSJed Brown   ierr = MatMatSolve(F,B,X);CHKERRQ(ierr);
266c4762a1bSJed Brown   ierr = MatDestroy(&F);CHKERRQ(ierr);
267c4762a1bSJed Brown 
268c4762a1bSJed Brown   /* Free space */
269c4762a1bSJed Brown   ierr = MatDestroy(&A);CHKERRQ(ierr);
270c4762a1bSJed Brown   ierr = MatDestroy(&Aher);CHKERRQ(ierr);
271c4762a1bSJed Brown   ierr = MatDestroy(&B);CHKERRQ(ierr);
272c4762a1bSJed Brown   ierr = MatDestroy(&C);CHKERRQ(ierr);
273c4762a1bSJed Brown   ierr = MatDestroy(&X);CHKERRQ(ierr);
274c4762a1bSJed Brown   ierr = VecDestroy(&b);CHKERRQ(ierr);
275c4762a1bSJed Brown   ierr = VecDestroy(&c);CHKERRQ(ierr);
276c4762a1bSJed Brown   ierr = VecDestroy(&d);CHKERRQ(ierr);
277c4762a1bSJed Brown   ierr = VecDestroy(&e);CHKERRQ(ierr);
278c4762a1bSJed Brown   ierr = VecDestroy(&x);CHKERRQ(ierr);
279c4762a1bSJed Brown   ierr = PetscRandomDestroy(&rand);CHKERRQ(ierr);
280c4762a1bSJed Brown   ierr = PetscFinalize();
281c4762a1bSJed Brown   return ierr;
282c4762a1bSJed Brown }
283c4762a1bSJed Brown 
284c4762a1bSJed Brown /*TEST
285c4762a1bSJed Brown 
286c4762a1bSJed Brown    build:
287c4762a1bSJed Brown       requires: elemental
288c4762a1bSJed Brown 
289c4762a1bSJed Brown    test:
290c4762a1bSJed Brown       nsize: 2
291c4762a1bSJed Brown       output_file: output/ex145.out
292c4762a1bSJed Brown 
293c4762a1bSJed Brown    test:
294c4762a1bSJed Brown       suffix: 2
295c4762a1bSJed Brown       nsize: 6
296c4762a1bSJed Brown       output_file: output/ex145.out
297c4762a1bSJed Brown 
298c4762a1bSJed Brown TEST*/
299