Sample mex file matlab

Use this subfolder name when copying the file to a writable folder. More Information - a link to a topic describing or using the example, or to the API function used in the example. Use the mex command to build the examples. To verify the compiler selected for the source code language lang , type:. Copy the file to a writable folder on your path using the following command syntax. Fill mxArray using mxGetDoubles.

Fill mxArray with non-double values. Fill mxArray using mxSetDoubles to allocate memory dynamically. Fill mxArray using mxSetComplexDoubles to allocate memory dynamically. Same as arrayProduct. Illustrate memory requirements of large mxArray. Create an uninitialized mxArray , fill with local data, and return. These examples link to one or both of the Fortran libraries mwlapack and mwblas.

Matlab provides library functions for a number of important operations, and many additional tasks may be accomplished by writing m-files from scratch.

But there are certain tasks that cannot be accomplished efficiently using the resources available within Matlab itself. Programs written for this interface must accept internal Matlab data structures as input, and produce similar structures as output.

They may then be compiled and called from the Matlab environment just like any other function. As an example, we will look at a mex-file for computing the 4-connected components of an image. Since the Image Processing Toolbox was introduced to Matlab, this function has been made obsolete by bwlabel.

In wizard, select "A DLL that exports some symbols" and press finish. Now everything is ready for building a MEX-file! In this situation, you must export mexFunction.

Here is an example:. In this example, input argument is an integer non-complex scalar n and output is a vector containing first n prime numbers. Copy Code. The name of your MEX file is arrayProduct. Every C program has a main function. Add the following mexFunction code.

This table describes the input parameters for mexFunction. Verify the number of MEX file input and output arguments using the nrhs and nlhs arguments. To check for two input arguments, multiplier and inMatrix , use this code. Use this code to check for one output argument, the product outMatrix.

Verify the argument types using the plhs and prhs arguments. This code validates that multiplier , represented by prhs[0] , is a scalar.

This code validates that inMatrix , represented by prhs[1] , is type double. Add the arrayProduct code.