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
 80: -    -matload_symmetric - matrix in file is symmetric

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

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

 90:    Level: beginner

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

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

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

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

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

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

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

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

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

149:   *newmat  = 0;

151:   if (!MatLoadRegisterAllCalled) {
152:     MatLoadRegisterAll(PETSC_NULL);
153:   }

155:   PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_BINARY,&isbinary);
156:   if (!isbinary) {
157:     SETERRQ(PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
158:   }

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

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

177:   PetscOptionsHasName(PETSC_NULL,"-matload_symmetric",&flg);
178:   if (flg) {
179:     MatSetOption(*newmat,MAT_SYMMETRIC);
180:   }
181:   PetscOptionsHasName(PETSC_NULL,"-help",&flg);
182:   if (flg) {MatLoadPrintHelp_Private(*newmat); }
183:   return(0);
184: }