Tables of MEX Function Source Code Examples

The following tables contain lists of source code files for creating example MEX functions. Use these examples as a starting point for creating your own MEX functions. The tables contain the following information.

Example Name - a link that opens the source file in MATLAB^® Editor for your convenience. You can use any code development editor to create source MEX files.
Example Subfolder - the subfolder of matlabroot/extern/examples containing the example. Use this subfolder name when copying the file to a writable folder.
Description - describes the example.
More Information - a link to a topic describing or using the example, or to the API function used in the example.

Getting Started

Use the mex command to build the examples. Make sure that you have a compiler installed that MATLAB supports. To verify the compiler selected for the source code language lang, type:

mex -setup lang

Copy the file to a writable folder on your path using the following command syntax. filename is the name of the example, and foldername is the subfolder name.

copyfile(fullfile(matlabroot,'extern','examples','foldername','filename'),'.','f')

For example, to copy arrayProduct.c, type:

copyfile(fullfile(matlabroot,'extern','examples','mex','arrayProduct.c'),'.','f')

C, C++, and Fortran MEX Functions

To build an example MEX function in MATLAB or at your operating system prompt, use this command syntax. filename is the example name, and release-option specifies the API used by the example. For information about the MATLAB APIs, see Choosing MEX Applications.

mex -v -release-option filename

Example Name	Example Subfolder	Description	More Information
`arrayFillGetPr.c`	`refbook`	Fill `mxArray` using `mxGetDoubles`.	Fill mxArray in C MEX File
`arrayFillSetData.c`	`refbook`	Fill `mxArray` with non-double values.	Fill mxArray in C MEX File
`arrayFillSetPr.c`	`refbook`	Fill `mxArray` using `mxSetDoubles` to allocate memory dynamically.	Fill mxArray in C MEX File
`arrayFillSetComplexPr.c`	`refbook`	Fill `mxArray` using `mxSetComplexDoubles` to allocate memory dynamically.	Fill mxArray in C MEX File
`arrayProduct.c`	`mex`	Multiply a scalar times 1xN matrix.	Create C Source MEX File arrayProduct.c
`arrayProduct.cpp`	`cpp_mex`	Same as `arrayProduct.c`, using the MATLAB Data API for C++.	C++ MEX Functions
`arraySize.c`	`mex`	Illustrate memory requirements of large `mxArray`.	Handling Large mxArrays in C MEX Files
`complexAdd.F`	`refbook`	Add two complex double arrays.
`convec.c` `convec.F`	`refbook`	Pass complex data.	Handle Complex Data in C MEX File
`dblmat.F` `compute.F`	`refbook`	Use of Fortran `%VAL`.
`doubleelement.c`	`refbook`	Use unsigned 16-bit integers.	Handle 8-, 16-, 32-, and 64-Bit Data in C MEX File
`explore.c`	`mex`	Identify data type of input variable.	Work with mxArrays
`findnz.c`	`refbook`	Use N-dimensional arrays.	Manipulate Multidimensional Numerical Arrays in C MEX Files
`fulltosparseIC.c` `fulltosparse.c` `fulltosparse.F`, `loadsparse.F`	`refbook`	Populate a sparse matrix.	Handle Sparse Arrays in C MEX File
`matsq.F`	`refbook`	Pass matrices in Fortran.
`matsqint8.F`	`refbook`	Pass non-double matrices in Fortran.
`mexatexit.c` `mexatexit.cpp`	`mex`	Register an exit function to close a data file.	C++ File Handling Example
`mexcallmatlab.c`	`mex`	Call built-in MATLAB `disp` function.
`mexcallmatlabwithtrap.c`	`mex`	How to capture error information.
`mexcpp.cpp`	`mex`	Illustrate some C++ language features in a MEX file built with the C Matrix API.	C++ Class Example
`mexevalstring.c`	`mex`	Use `mexEvalString` to assign variables in MATLAB.	`mexEvalString`
`mexfunction.c`	`mex`	How to use `mexFunction`.	`mexFunction`
`mxgetproperty.c`	`mex`	Use `mxGetProperty` and `mxSetProperty` to change the `Color` property of a graphic object.	`mxGetProperty` and `mxSetProperty`
`mexgetarray.c`	`mex`	Use `mexGetVariable` and `mexPutVariable` to track counters in the MEX file and in the MATLAB global workspace.	`mexGetVariable` and `mexPutVariable`
`mexgetarray.cpp`		Same as `mexgetarray.c`, using getVariable and setVariable in the MATLAB Data API for C++.	Set and Get MATLAB Variables from MEX
`mexlock.c` `mexlockf.F`	`mex`	How to lock and unlock a MEX file.	`mexLock`
`mxcalcsinglesubscript.c`	`mx`	Demonstrate MATLAB 1-based matrix indexing versus C 0-based indexing.	`mxCalcSingleSubscript`
`mxcreatecellmatrix.c` `mxcreatecellmatrixf.F`	`mx`	Create 2-D cell array.	Create 2-D Cell Array in C MEX File
`mxcreatecharmatrixfromstr.c`	`mx`	Create 2-D character array.	`mxCreateCharMatrixFromStrings`
`mxcreatestructarray.c`	`mx`	Create MATLAB structure from C structure.	`mxCreateStructArray`
`mxcreateuninitnumericmatrix.c`	`mx`	Create an uninitialized `mxArray`, fill with local data, and return.	`mxCreateUninitNumericMatrix`
`mxgeteps.c` `mxgetepsf.F`	`mx`	Read MATLAB `eps` value.	`mxGetEps`
`mxgetinf.c`	`mx`	Read `inf` value.	`mxGetInf`
`mxgetnzmax.c`	`mx`	Display number of nonzero elements in a sparse matrix and maximum number of nonzero elements it can store.	`mxGetNzmax`
`mxisclass.c`	`mx`	Check if array is member of specified class.	`mxIsClass`
`mxisfinite.c`	`mx`	Check for `NaN` and infinite values.	`mxIsFinite`
`mxislogical.c`	`mx`	Check if workspace variable is logical or global.	`mxIsLogical`
`mxisscalar.c`	`mx`	Check if input variable is scalar.	`mxIsScalar`
`mxmalloc.c`	`mx`	Allocate memory to copy a MATLAB `char` array to a C-style string.	`mxMalloc`
`mxsetdimensions.c` `mxsetdimensionsf.F`	`mx`	Reshape an array.	`mxSetDimensions`
`mxsetnzmax.c`	`mx`	Reallocate memory for sparse matrix and reset values of `pr`, `pi`, `ir`, and `nzmax`.	`mxSetNzmax`
`passstr.F`	`refbook`	Pass C character matrix from Fortran to MATLAB.
`phonebook.c`	`refbook`	Manipulate structures and cell arrays.	Pass Structures and Cell Arrays in C MEX File
`phonebook.cpp`	`cpp_mex`	Same as `phonebook.c`, using the MATLAB Data API for C++.	C++ MEX Functions
`revord.c` `revord.F`	`refbook`	Copy MATLAB `char` array to and from C-style string.	Pass Strings in C MEX File
`sincall.c` `sincall.F`, `fill.F`	`refbook`	Create `mxArray` and pass to MATLAB `sin` and `plot` functions.
`timestwo.c` `timestwo.F`	`refbook`	Demonstrate common workflow of MEX file.	Pass Scalar Values in C MEX File
`xtimesy.c` `xtimesy.F`	`refbook`	Pass multiple parameters.
`yprime.c` `yprimef.F`, `yprimefg.F`	`mex`	Solve simple three body orbit problem.
`yprime.cpp`	`cpp_mex`	Same as `yprime.c`, using the MATLAB Data API for C++.	C++ MEX Functions

MEX Functions Calling Fortran Subroutines

The examples in this table call a LAPACK or BLAS function from a MEX function. The examples link to one or both of the Fortran libraries mwlapack and mwblas. To build the MEX function, follow the instructions in the topics listed in the More Information column.

Example Name	Example Subfolder	Description	More Information
`dotProductComplexIC.c` `dotProductComplexIC.F` `dotProductComplex.c`	`refbook`	Handle Fortran complex return type for function called from a C or Fortran MEX file. `dotProductComplexIC.c` and `dotProductComplexIC.F` use the interleaved complex API. `dotProductComplex.c` uses the separate complex API.	Handle Fortran Complex Return Type — dotProductComplex
`matrixDivide.c`	`refbook`	Call a LAPACK function.	Preserve Input Values from Modification
`matrixDivideComplex.c`	`refbook`	Call a LAPACK function with complex numbers.	Pass Complex Variables — matrixDivideComplex
`matrixMultiply.c`	`refbook`	Call a BLAS function.	Pass Arguments to Fortran Functions from C/C++ Programs
`utdu_slv.c`	`refbook`	Use LAPACK for symmetric indefinite factorization.	Symmetric Indefinite Factorization Using LAPACK — utdu_slv