Actual source code: matio.c

  1: /*$Id: matio.c,v 1.79 2001/08/06 21:16:10 bsmith Exp $*/

  3: /* 
  4:    This file contains simple binary read/write routines for matrices.
  5:  */

 7:  #include src/mat/matimpl.h
 8:  #include petscsys.h
  9: PetscTruth MatLoadRegisterAllCalled = PETSC_FALSE;
 10: PetscFList      MatLoadList              = 0;

 12: /*@C
 13:     MatLoadRegister - Allows one to register a routine that reads matrices
 14:         from a binary file for a particular matrix type.

 16:   Not Collective

 18:   Input Parameters:
 19: +   type - the type of matrix (defined in include/petscmat.h), for example, MATSEQAIJ.
 20: -   loader - the function that reads the matrix from the binary file.

 22:   Level: developer

 24: .seealso: MatLoadRegisterAll(), MatLoad()

 26: @*/
 27: int MatLoadRegister(char *sname,char *path,char *name,int (*function)(PetscViewer,MatType,Mat*))
 28: {
 29:   int  ierr;
 30:   char fullname[256];

 33:   PetscFListConcat(path,name,fullname);
 34:   PetscFListAdd(&MatLoadList,sname,fullname,(void (*)(void))function);
 35:   return(0);
 36: }

 38: static int MatLoadPrintHelp_Private(Mat A)
 39: {
 40:   static PetscTruth called = PETSC_FALSE;
 41:   MPI_Comm          comm = A->comm;
 42:   int               ierr;
 43: 
 45:   if (called) {return(0);} else called = PETSC_TRUE;
 46:   (*PetscHelpPrintf)(comm," Options for MatLoad:n");
 47:   (*PetscHelpPrintf)(comm,"  -mat_type <type>n");
 48:   (*PetscHelpPrintf)(comm,"  -matload_type <type>n");
 49:   (*PetscHelpPrintf)(comm,"  -matload_block_size <block_size> :Used for MATBAIJ, MATBDIAGn");
 50:   (*PetscHelpPrintf)(comm,"  -matload_bdiag_diags <s1,s2,s3,...> : Used for MATBDIAGn");
 51:   return(0);
 52: }

 54: /*@C
 55:    MatLoad - Loads a matrix that has been stored in binary format
 56:    with MatView().  The matrix format is determined from the options database.
 57:    Generates a parallel MPI matrix if the communicator has more than one
 58:    processor.  The default matrix type is AIJ.

 60:    Collective on PetscViewer

 62:    Input Parameters:
 63: +  viewer - binary file viewer, created with PetscViewerBinaryOpen()
 64: -  outtype - type of matrix desired, for example MATSEQAIJ,
 65:              MATMPIROWBS, etc.  See types in petsc/include/petscmat.h.

 67:    Output Parameters:
 68: .  newmat - new matrix

 70:    Basic Options Database Keys:
 71: +    -matload_type seqaij   - AIJ type
 72: .    -matload_type mpiaij   - parallel AIJ type
 73: .    -matload_type seqbaij  - block AIJ type
 74: .    -matload_type mpibaij  - parallel block AIJ type
 75: .    -matload_type seqbdiag - block diagonal type
 76: .    -matload_type mpibdiag - parallel block diagonal type
 77: .    -matload_type mpirowbs - parallel rowbs type
 78: .    -matload_type seqdense - dense type
 79: -    -matload_type mpidense - parallel dense type

 81:    More Options Database Keys:
 82:    Used with block matrix formats (MATSEQBAIJ, MATMPIBDIAG, ...) to specify
 83:    block size
 84: .    -matload_block_size <bs>

 86:    Used to specify block diagonal numbers for MATSEQBDIAG and MATMPIBDIAG formats
 87: .    -matload_bdiag_diags <s1,s2,s3,...>

 89:    Level: beginner

 91:    Notes:
 92:    MatLoad() automatically loads into the options database any options
 93:    given in the file filename.info where filename is the name of the file
 94:    that was passed to the PetscViewerBinaryOpen(). The options in the info
 95:    file will be ignored if you use the -matload_ignore_info option.

 97:    In parallel, each processor can load a subset of rows (or the
 98:    entire matrix).  This routine is especially useful when a large
 99:    matrix is stored on disk and only part of it existsis desired on each
100:    processor.  For example, a parallel solver may access only some of
101:    the rows from each processor.  The algorithm used here reads
102:    relatively small blocks of data rather than reading the entire
103:    matrix and then subsetting it.

105:    Notes for advanced users:
106:    Most users should not need to know the details of the binary storage
107:    format, since MatLoad() and MatView() completely hide these details.
108:    But for anyone who's interested, the standard binary matrix storage
109:    format is

111: $    int    MAT_FILE_COOKIE
112: $    int    number of rows
113: $    int    number of columns
114: $    int    total number of nonzeros
115: $    int    *number nonzeros in each row
116: $    int    *column indices of all nonzeros (starting index is zero)
117: $    PetscScalar *values of all nonzeros

119:    Note for Cray users, the int's stored in the binary file are 32 bit
120: integers; not 64 as they are represented in the memory, so if you
121: write your own routines to read/write these binary files from the Cray
122: you need to adjust the integer sizes that you read in, see
123: PetscReadBinary() and PetscWriteBinary() to see how this may be
124: done.

126:    In addition, PETSc automatically does the byte swapping for
127: machines that store the bytes reversed, e.g.  DEC alpha, freebsd,
128: linux, nt and the paragon; thus if you write your own binary
129: read/write routines you have to swap the bytes; see PetscReadBinary()
130: and PetscWriteBinary() to see how this may be done.

132: .keywords: matrix, load, binary, input

134: .seealso: PetscViewerBinaryOpen(), MatView(), VecLoad(), MatLoadRegister(),
135:           MatLoadRegisterAll()

137:  @*/
138: int MatLoad(PetscViewer viewer,MatType outtype,Mat *newmat)
139: {
140:   int         ierr;
141:   PetscTruth  isbinary,flg;
142:   MPI_Comm    comm;
143:   int         (*r)(PetscViewer,MatType,Mat*);
144:   char        mtype[256];

148:   *newmat  = 0;

150:   if (!MatLoadRegisterAllCalled) {
151:     MatLoadRegisterAll(PETSC_NULL);
152:   }

154:   PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_BINARY,&isbinary);
155:   if (!isbinary) {
156:     SETERRQ(PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
157:   }

159:   PetscOptionsGetString(PETSC_NULL,"-mat_type",mtype,256,&flg);
160:   if (flg) {
161:     outtype = mtype;
162:   }
163:   PetscOptionsGetString(PETSC_NULL,"-matload_type",mtype,256,&flg);
164:   if (flg) {
165:     outtype = mtype;
166:   }
167:   PetscObjectGetComm((PetscObject)viewer,&comm);
168:   if (!outtype) outtype = MATMPIAIJ;
169:    PetscFListFind(comm,MatLoadList,outtype,(void(**)(void))&r);
170:   if (!r) SETERRQ1(1,"Unknown Mat type given: %s",outtype);

172:   PetscLogEventBegin(MAT_Load,viewer,0,0,0);
173:   (*r)(viewer,outtype,newmat);
174:   PetscLogEventEnd(MAT_Load,viewer,0,0,0);

176:   PetscOptionsHasName(PETSC_NULL,"-help",&flg);
177:   if (flg) {MatLoadPrintHelp_Private(*newmat); }
178:   return(0);
179: }