This module provides a simple interface to write MATLAB .mat files. It is not intended to be a complete implementation of the .mat file format, but rather a simple way to write data from Fortran to MATLAB. The module is written in Fortran 2003 and should be compatible with most compilers. It has been tested with gfortran 12.

The module provides a single type, matfile, which is used to open and write to a .mat file. The type has a single procedure, write, which can be used to write a single array to the file. The array can be of any rank, and the array name can be any string. The array is written as a double precision array, regardless of the precision of the input array.

Example:

use formatio
type(matfile) :: mf

real*8, dimension(10) :: x
x = 1.0
call mf%open('test.mat', 'write')
call mf%write('x', x)
call mf%close()