External Interfaces/API

Using MEX-Files

MEX-files are subroutines produced from C or Fortran source code. They behave just like M-files and built-in functions. While M-files have a platform-independent extension, .m, MATLAB identifies MEX-files by platform-specific extensions. This table lists the platform-specific extensions for MEX-files.

Table 1-1: MEX-File Extensions  

Platform	MEX-File Extension
Alpha	mexaxp
HP, Version 10.20	mexhp7
HP, Version 11.x	mexhpux
IBM RS/6000	mexrs6
Linux	mexglx
SGI, SGI64	mexsg
Solaris	mexsol
Windows	dll

You can call MEX-files exactly as you would call any M-function. For example, a MEX-file called conv2.mex on your disk in the MATLAB datafun toolbox directory performs a 2-D convolution of matrices. conv2.m only contains the help text documentation. If you invoke the function conv2 from inside MATLAB, the interpreter looks through the list of directories on the MATLAB search path. It scans each directory looking for the first occurrence of a file named conv2 with the corresponding filename extension from the table or .m. When it finds one, it loads the file and executes it. MEX-files take precedence over M-files when like-named files exist in the same directory. However, help text documentation is still read from the .m file.

Introducing MEX-Files

The Distinction Between mx and mex Prefixes