load from and save to mat-files

libmatfile is C library which allow to load array and matrices from or store them into mat-file. This library was separated as isolated module during cutt project development. It is implemented specification of MAT-file format according to documentation.

At the moment all features are not implemented yet. The list of capabilities and their readiness is placed bellow.

• Simple file loader.
• Streaming file loading.
• Simple file saver.
• Streaming file saving.
• Memory map support for large files.
• C++ wrapper and bindings to other languages if needed.
• MAT-file Level 4 support.
• Coverage and unit testing.

The list is not filled completely yet since library is under development and not all API routines are stable.

Suppose there is a mat-file which contains at least one matrix. The matrix is The matrix is Hilbert if the following holds.

Maybe the matrix is adjacency matrix of social graph or item-feature matrix of recommender system. In either case, we need to load the matrix and perform some calculations. There is an example of how to archive these things below.

#include <matfile/matfile.h>

matfile_t *mat = matfile_read("arrays.mat");
const char **varnames = matfile_who(mat);

for (unsigned i = 0; varnames + i != NULL; ++i) {
    printf("[%03d] variable %s\n", varnames + i);
}

free((void *)varnames);

matfile_array_t *array = matfile_get_array(mat, "hilbert");
matfile_destroy(mat);

The build system used by libmatfile is CMake which is natural for C/C++ projects. In order to build release version one should run the following commands in shell.

mkdir build
cd build
cmake ..
make

After compilation libmatfile.a or libmatfile.so depending on desired linking mechanism appears in build directory. Moreover, there is doxygen documentation in doc/html/index.html relative to build directory as well. See details in CMakeLists.txt.

On default documentation is built with library. One can control doc generation on uild with DOXYGEN_HTML. The following code snippet shows how to disable HTML documentation output.

cmake .. -DDOXYGEN_HTML=OFF

The latest documentation is already generated and the online version is provided here.

Similar to documentation generation tests are built on default. There is built-in option BUILD_TESTING which controls adding testing targets to global target.

cmake .. -DBUILD_TESTING=ON
ctest  # or for more verbosity ./matfile-test

The previous commands force building tests and run ctest for brief output. The testing is based on top of Google Test framework so executable matfile-test produces more detailed output that could be usefull for developers.

© Daniel Bershatsky <mailto:[email protected]>, 2018