xref: /petsc/src/mat/impls/sbaij/seq/aijsbaij.c (revision a617505687127600a4a515cb47d9e60889c09ca3)
1 /*$Id: aijsbaij.c,v 1.9 2001/08/07 03:02:55 balay Exp $*/
2 
3 #include "src/mat/impls/aij/seq/aij.h"
4 #include "src/mat/impls/sbaij/seq/sbaij.h"
5 
6 EXTERN_C_BEGIN
7 #undef __FUNCT__
8 #define __FUNCT__ "MatConvert_SeqAIJ_SeqSBAIJ"
9 int MatConvert_SeqAIJ_SeqSBAIJ(Mat A,MatType newtype,Mat *B)
10 {
11   Mat_SeqAIJ   *a = (Mat_SeqAIJ*)A->data;
12   Mat_SeqSBAIJ *b;
13   int          ierr,*ai=a->i,*aj,m=A->M,n=A->N,i,j,
14                *bi=b->i,*bj=b->j,*rowlengths;
15   PetscScalar  *av,*bv;
16 
17   PetscFunctionBegin;
18   if (n != m) SETERRQ(PETSC_ERR_SUP,"Matrix must be a square matrix");
19   if (!a->diag){
20     ierr = MatMarkDiagonal_SeqAIJ(A);CHKERRQ(ierr);
21   }
22 
23   ierr = PetscMalloc(m*sizeof(int),&rowlengths);CHKERRQ(ierr);
24   for (i=0; i<m; i++) {
25     rowlengths[i] = ai[i+1] - a->diag[i];
26   }
27   ierr = MatCreateSeqSBAIJ(PETSC_COMM_SELF,1,m,n,0,rowlengths,B);CHKERRQ(ierr);
28 
29   ierr = MatSetOption(*B,MAT_ROW_ORIENTED);CHKERRQ(ierr);
30   ierr = MatSetOption(*B,MAT_ROWS_SORTED);CHKERRQ(ierr);
31   ierr = MatSetOption(*B,MAT_COLUMNS_SORTED);CHKERRQ(ierr);
32 
33   b  = (Mat_SeqSBAIJ*)(*B)->data;
34   bi = b->i;
35   bj = b->j;
36   bv = b->a;
37 
38   bi[0] = 0;
39   for (i=0; i<m; i++) {
40     aj = a->j + a->diag[i];
41     av = a->a + a->diag[i];
42     for (j=0; j<rowlengths[i]; j++){
43       *bj = *aj; bj++; aj++;
44       *bv = *av; bv++; av++;
45     }
46     bi[i+1]    = bi[i] + rowlengths[i];
47     b->ilen[i] = rowlengths[i];
48   }
49 
50   ierr = PetscFree(rowlengths);CHKERRQ(ierr);
51   ierr = MatAssemblyBegin(*B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
52   ierr = MatAssemblyEnd(*B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
53   PetscFunctionReturn(0);
54 }
55 EXTERN_C_END
56 
57