Actual source code: baijsolvtran1.c

petsc-master 2019-12-08
Report Typos and Errors
```  1:  #include <../src/mat/impls/baij/seq/baij.h>
2:  #include <petsc/private/kernels/blockinvert.h>

4: PetscErrorCode MatSolveTranspose_SeqBAIJ_1(Mat A,Vec bb,Vec xx)
5: {
6:   Mat_SeqBAIJ       *a    = (Mat_SeqBAIJ*)A->data;
7:   IS                iscol = a->col,isrow = a->row;
8:   PetscErrorCode    ierr;
9:   const PetscInt    *rout,*cout,*r,*c,*adiag = a->diag,*ai = a->i,*aj = a->j,*vi;
10:   PetscInt          i,n = a->mbs,j;
11:   PetscInt          nz;
12:   PetscScalar       *x,*tmp,s1;
13:   const MatScalar   *aa = a->a,*v;
14:   const PetscScalar *b;

18:   VecGetArray(xx,&x);
19:   tmp  = a->solve_work;

21:   ISGetIndices(isrow,&rout); r = rout;
22:   ISGetIndices(iscol,&cout); c = cout;

24:   /* copy the b into temp work space according to permutation */
25:   for (i=0; i<n; i++) tmp[i] = b[c[i]];

27:   /* forward solve the U^T */
28:   for (i=0; i<n; i++) {
29:     v   = aa + adiag[i+1] + 1;
30:     vi  = aj + adiag[i+1] + 1;
32:     s1  = tmp[i];
33:     s1 *= v[nz];  /* multiply by inverse of diagonal entry */
34:     for (j=0; j<nz; j++) tmp[vi[j]] -= s1*v[j];
35:     tmp[i] = s1;
36:   }

38:   /* backward solve the L^T */
39:   for (i=n-1; i>=0; i--) {
40:     v  = aa + ai[i];
41:     vi = aj + ai[i];
42:     nz = ai[i+1] - ai[i];
43:     s1 = tmp[i];
44:     for (j=0; j<nz; j++) tmp[vi[j]] -= s1*v[j];
45:   }

47:   /* copy tmp into x according to permutation */
48:   for (i=0; i<n; i++) x[r[i]] = tmp[i];

50:   ISRestoreIndices(isrow,&rout);
51:   ISRestoreIndices(iscol,&cout);
53:   VecRestoreArray(xx,&x);

55:   PetscLogFlops(2.0*a->nz-A->cmap->n);
56:   return(0);
57: }

59: PetscErrorCode MatSolveTranspose_SeqBAIJ_1_inplace(Mat A,Vec bb,Vec xx)
60: {
61:   Mat_SeqBAIJ       *a   =(Mat_SeqBAIJ*)A->data;
62:   IS                iscol=a->col,isrow=a->row;
63:   PetscErrorCode    ierr;
64:   const PetscInt    *r,*c,*rout,*cout;
65:   const PetscInt    *diag=a->diag,n=a->mbs,*vi,*ai=a->i,*aj=a->j;
66:   PetscInt          i,nz;
67:   const MatScalar   *aa=a->a,*v;
68:   PetscScalar       s1,*x,*t;
69:   const PetscScalar *b;

73:   VecGetArray(xx,&x);
74:   t    = a->solve_work;

76:   ISGetIndices(isrow,&rout); r = rout;
77:   ISGetIndices(iscol,&cout); c = cout;

79:   /* copy the b into temp work space according to permutation */
80:   for (i=0; i<n; i++) t[i] = b[c[i]];

82:   /* forward solve the U^T */
83:   for (i=0; i<n; i++) {

85:     v = aa + diag[i];
86:     /* multiply by the inverse of the block diagonal */
87:     s1 = (*v++)*t[i];
88:     vi = aj + diag[i] + 1;
89:     nz = ai[i+1] - diag[i] - 1;
90:     while (nz--) {
91:       t[*vi++] -= (*v++)*s1;
92:     }
93:     t[i] = s1;
94:   }
95:   /* backward solve the L^T */
96:   for (i=n-1; i>=0; i--) {
97:     v  = aa + diag[i] - 1;
98:     vi = aj + diag[i] - 1;
99:     nz = diag[i] - ai[i];
100:     s1 = t[i];
101:     while (nz--) {
102:       t[*vi--] -=  (*v--)*s1;
103:     }
104:   }

106:   /* copy t into x according to permutation */
107:   for (i=0; i<n; i++) x[r[i]] = t[i];

109:   ISRestoreIndices(isrow,&rout);
110:   ISRestoreIndices(iscol,&cout);