Storage

Table of contents Coordinate I/O Vector I/O Matrix I/O Grid I/O

𝓗𝖫𝖨𝖡𝗉𝗋𝗈 supports several file formats for reading/writing coordinates, vectors, matrices and files, e.g. Matlab, Harwell/Boeing, MatrixMarket, SAMG, PLY, Gmsh, SurfaceMesh. However, not all features of each file format is fully implemented in 𝓗𝖫𝖨𝖡𝗉𝗋𝗈, e.g. only a single object may be written to Matlab files and only triangular grids are supported in corresponding file formats.

Remarks

All I/O classes will automatically add a corresponding filename suffix, e.g. ".hm" in case of HLIBpro file format, if no suffix is present.

Coordinate I/O

Vector I/O

Matrix I/O

The following file formats are supported for reading and writing matrices:

Format	Class	Remarks
𝓗𝖫𝖨𝖡𝗉𝗋𝗈 format	THLibMatrixIO	𝓗-, sparse and dense matrices (only format for 𝓗-matrices!).
Matlab v5	TMatlabMatrixIO	sparse and dense matrices in single and double precision when writing files, only a single object may be stored limited support for reading from structures support for compression via zlib
Harwell/Boeing Harwell/Rutherford	THBMatrixIO	sparse matrix format no read support for elemental matrices
MatrixMarket	TMMMatrixIO	sparse matrix format only reading supported only unsymmetric matrices supported no support for array format
SAMG	TSAMGMatrixIO	sparse matrix format

All storage classes implement the same basic interface defined by the functions:

virtual void      write ( const TMatrix * A, const String & name ) const;
virtual TMatrix * read  ( const String & name ) const;

Furthermore, a class for reading/writing matrices with file format autodetection is available (TAutoMatrixIO). In case of reading from a file, the auto detection works by actually looking at the stored data and hence, is very robust in choosing the correct file format. On the other hand, if data output is used, only the file name is used to decide the format. The following rules apply based on the file name extension:

Extension	File Format
hm	HLIBpro format
mat, m	Matlab format
hb, rb, rua, rsa, psa	Harwell/Boeing format
mtx	MatrixMarket format
amg	SAMG format

The I/O functions from TAutoMatrixIO are also available in direct from via the functions:

TMatrix *  read_matrix   ( const char *     filename );
void       write_matrix  ( const TMatrix *  A,
                           const char *     filename );

If the file format supports named storage, e.g. Matlab, the corresponding matrix name may be provided by an additional argument:

TMatrix *  read_matrix   ( const char *     filename,
                           const char *     matname );
void       write_matrix  ( const TMatrix *  A,
                           const char *     filename,
                           const char *     matname );

For all other file formats, this parameter will be ignored.

Grid I/O