FortranMATLAB

FortranMATLAB is a term used to describe approaches and tools that enable interoperability between Fortran and MATLAB. It covers methods to call Fortran subroutines from MATLAB, exchange data efficiently, and integrate Fortran-implemented numerical kernels into MATLAB workflows.

In scientific computing, engineering, and high-performance computing, researchers often maintain legacy Fortran code or rely on Fortran’s performance for numerically intensive routines. FortranMATLAB workflows allow these routines to be reused within MATLAB’s scripting, visualization, and prototyping environment.

Two common technical approaches are used. The first relies on MATLAB’s loadlibrary and calllib to link against a Fortran-compiled shared library that exposes a C-compatible interface. The second uses MEX wrappers, where a C or C++ MEX file calls Fortran code directly or via a thin C layer. Fortran routines intended for interoperation typically use the ISO_C_BINDING module with BIND(C) to provide a stable C ABI.

Data exchange between MATLAB and Fortran can be done by passing pointers to numeric arrays through the C wrapper, with attention to memory layout. MATLAB uses column-major order, and Fortran follows a compatible column-major layout; when crossing through a C interface, wrappers must handle indexing correctly. MATLAB can pass arrays, scalars, and structures to Fortran and receive results back as arrays or scalars.

Practical considerations include data transfer overhead, the need for consistent data types and precisions, compiler and platform compatibility, and debugging complexity. Alternatives include using MATLAB’s built-in MEX interfaces with C/C++, or re-implementing critical kernels in MATLAB or Python, depending on project constraints.