xref: /petsc/src/mat/utils/matio.c (revision b4874afa33ef89d436bd5cc157aada57df95d045) !
1 #ifndef lint
2 static char vcid[] = "$Id: matio.c,v 1.20 1995/10/26 21:45:14 curfman Exp bsmith $";
3 #endif
4 
5 /*
6    This file contains simple binary read/write routines for matrices.
7  */
8 
9 #include "petsc.h"
10 #include "vec/vecimpl.h"
11 #include "../matimpl.h"
12 #include "sysio.h"
13 #include "pinclude/pviewer.h"
14 
15 extern int MatLoad_MPIRowbs(Viewer,MatType,Mat*);
16 extern int MatLoad_SeqAIJ(Viewer,MatType,Mat*);
17 extern int MatLoad_MPIAIJ(Viewer,MatType,Mat*);
18 extern int MatLoad_SeqBDiag(Viewer,MatType,Mat*);
19 extern int MatLoad_MPIBDiag(Viewer,MatType,Mat*);
20 extern int MatLoad_SeqDense(Viewer,MatType,Mat*);
21 extern int MatLoad_MPIDense(Viewer,MatType,Mat*);
22 
23 /*@C
24    MatLoad - Loads a matrix that has been stored in binary format
25    with MatView().
26 
27    Input Parameters:
28 .  bview - binary file viewer, created with ViewerFileOpenBinary()
29 .  outtype - type of matrix desired, for example MATSEQAIJ,
30    MATMPIROWBS, etc.  See types in petsc/include/mat.h.
31 
32    Output Parameters:
33 .  newmat - new matrix
34 
35    Notes:
36    In parallel, each processor can load a subset of rows (or the
37    entire matrix).  This routine is especially useful when a large
38    matrix is stored on disk and only part of it is desired on each
39    processor.  For example, a parallel solver may access only some of
40    the rows from each processor.  The algorithm used here reads
41    relatively small blocks of data rather than reading the entire
42    matrix and then subsetting it.
43 
44    Notes for advanced users:
45    Most users should not need to know the details of the binary storage
46    format, since MatLoad() and MatView() completely hide these details.
47    But for anyone who's interested, the standard binary matrix storage
48    format is
49 
50 $    int    MAT_COOKIE
51 $    int    number of rows
52 $    int    number of columns
53 $    int    total number of nonzeros
54 $    int    *number nonzeros in each row
55 $    int    *column indices of all nonzeros (starting index is zero)
56 $    Scalar *values of all nonzeros
57 
58 .keywords: matrix, load, binary, input
59 
60 .seealso: ViewerFileOpenBinary(), MatView(), VecLoad()
61  @*/
62 int MatLoad(Viewer bview,MatType outtype,Mat *newmat)
63 {
64   PetscObject vobj = (PetscObject) bview;
65   int         ierr,set;
66   MatType     type;
67   *newmat = 0;
68 
69   PETSCVALIDHEADERSPECIFIC(vobj,VIEWER_COOKIE);
70   if (vobj->type != BINARY_FILE_VIEWER)
71    SETERRQ(1,"MatLoad: Invalid viewer; open viewer with ViewerFileOpenBinary()");
72 
73   PLogEventBegin(MAT_Load,bview,0,0,0);
74   ierr = MatGetFormatFromOptions(vobj->comm,0,&type,&set); CHKERRQ(ierr);
75   if (!set) type = outtype;
76 
77   if (type == MATSEQAIJ) {
78     ierr = MatLoad_SeqAIJ(bview,type,newmat); CHKERRQ(ierr);
79   }
80   else if (type == MATMPIAIJ) {
81     ierr = MatLoad_MPIAIJ(bview,type,newmat); CHKERRQ(ierr);
82   }
83   else if (type == MATSEQBDIAG) {
84     ierr = MatLoad_SeqBDiag(bview,type,newmat); CHKERRQ(ierr);
85   }
86   else if (type == MATMPIBDIAG) {
87     ierr = MatLoad_MPIBDiag(bview,type,newmat); CHKERRQ(ierr);
88   }
89   else if (type == MATSEQDENSE) {
90     ierr = MatLoad_SeqDense(bview,type,newmat); CHKERRQ(ierr);
91   }
92   else if (type == MATMPIDENSE) {
93     ierr = MatLoad_MPIDense(bview,type,newmat); CHKERRQ(ierr);
94   }
95 #if defined(HAVE_BLOCKSOLVE) && !defined(__cplusplus)
96   else if (type == MATMPIROWBS) {
97     ierr = MatLoad_MPIRowbs(bview,type,newmat); CHKERRQ(ierr);
98   }
99 #endif
100   else {
101     SETERRQ(1,"MatLoad: cannot load with that matrix type yet");
102   }
103 
104   PLogEventEnd(MAT_Load,bview,0,0,0);
105   return 0;
106 }
107