Mat File Versions

Currently only the uncompressed mat version 5 file format 6 is supported that is compressed mat files cannot be written only read.

Mat file versions.

Apparently there was a nocompression flag that worked in previous versions of save. The only exception to this is when you create new mat files using the matfile function. Starting with mat file version 4 there are several subsequent versions of mat files that support an increasing set of features. While continuing to use the same general structure new format versions have been introduced to support new capabilities.

Matlab 7 5 r2007b 18 1 6 0 september 1 2007 last release for windows 2000 and powerpc mac. But this is no longer supported. Hdf5 based mat file support matlab 7 4 r2007a 17 1 5 0 07 2007 march 1 2007 new bsxfun function to apply element by element binary operation with singleton expansion enabled. Matlab releases r2006b and later all support all mat file versions.

For example data compression and unicode support. Version 7 3 of mat files uses hdf5 format this format has a significant storage overhead to describe the contents of the file especially so for complex nested cellarrays and structures. A file with the mat file extension is most likely a microsoft access table shortcut file that s used to quickly open a table without having to first open the ms access program. Unfortunately v7 3 appears to have some form of compression algorithm embedded saving and loading these v7 3 mat files istaking significant time.

Matlab releases r2006b and later all support all mat file versions. Starting with mat file version 4 there are several subsequent versions of mat files that support an increasing set of features. New internal format for p code. By default all save operations create version 7 mat files.

Moreover the maximum variable size supported by the mat version 5 file format is 2 31 bytes 6. One distinction is by level level 4 and level 5 files have completely different technical structures. The naming of the mat file format versions is somewhat confusing. Its main advantage over previous versions of mat files is that it allows storing data larger than 2gb on 64 bit systems.

The only exception to this is when you create new mat files using the matfile function.