Write C++ Functions Callable from MATLAB (MEX Files)
Use the C++ MEX API to create MATLAB functions that provide the efficiency of C++ programs and that can access external functions and libraries from MATLAB. The C++ MEX API provides these features:
Uses modern C++ programming features and object-oriented designs.
Calls MATLAB functions from the MEX function.
Integrates seamlessly into MATLAB, getting inputs from and returning results to MATLAB.
Supports MATLAB data types and copy-on-write semantics.
Writes thread-safe multi-threaded MEX functions.
Executes C++ MEX functions out-of-process.
Note
Functions in the MATLAB C++ APIs use the matlab::data::Array
class
defined in the MATLAB Data API for C++. If your MEX functions must run
in MATLAB R2017b or earlier, or if you prefer to work in the C language,
then use the C Matrix API, which
works with the mxArray
data structure
instead. For more information, see Write C Functions Callable from MATLAB (MEX Files).
Topics
Create C++ MEX Functions
- C++ MEX Functions
MEX files implement MATLAB functions written in C++. - Create a C++ MEX Source File
How to create a basic C++ MEX function.
Setup and Build MEX Files
- Build C++ MEX Programs
Build MEX applications on different platforms. - Test Your Build Environment
Test your build environment with a predefined C++ MEX file. - C++ MEX API
Use C++11 features and the C++ Engine API to implement MEX functions.
Design of C++ MEX Functions
- Structure of C++ MEX Function
Implement a class that overrides the function call operator()
to create a functor object. - Avoid Copies of Arrays in MEX Functions
Techniques to avoid making copies of large arrays to reduce memory usage and improve execution speed. - Managing External Resources from MEX Functions
Customize theMexFunction
class to better handle the resources used by your MEX function. - Handling Inputs and Outputs
Check the size and type of inputs and display error messages in MATLAB. - Displaying Output in MATLAB Command Window
MEX functions can display output in the MATLAB command window. - Making async Requests Using mexCallMATLAB
Behavior when calling back into MATLAB with anasync
request likematlab::engine::MATLABEngine::fevalAsync
.
MATLAB Data Types in MEX Functions
- Data Access in Typed, Cell, and Structure Arrays
Cell and structure arrays let you write to array contents without copying entire array. - Data Types for Passing MEX Function Data
Define the correct data types to pass data between MATLAB and MEX functions.
Call MATLAB Functions
- Call MATLAB Functions from MEX Functions
Call MATLAB functions, passing arguments from and returning arguments to a MEX function. - Catch Exceptions in MEX Function
Catch exceptions thrown in a MEX function. - Execute MATLAB Statements from MEX Function
Execute MATLAB statements to create variables in the caller's workspace.
Separate Threads and Processes
- Call MATLAB from Separate Threads in MEX Function
MEX functions can call MATLAB from user-created threads using the C++ Engine asynchronous API. - Out-of-Process Execution of C++ MEX Functions
Execute C++ MEX functions in processes that are separate from the MATLAB process.
Access MATLAB Variables
- Set and Get MATLAB Variables from MEX
Put variables into or get variables from the MATLAB base and global workspaces. - MATLAB Objects in MEX Functions
Pass MATLAB objects to MEX functions. - Using MEX Functions for MATLAB Class Methods
You can use MEX functions to implement methods for MATLAB classes.