mexFunction (C) - Entry point to C/C++ MEX function built with C Matrix API - MATLAB (original) (raw)
Entry point to C/C++ MEX function built with C Matrix API
C Syntax
#include "mex.h" void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
Description
mexFunction is not a routine you call. Rather,mexFunction is the name of the gateway function in C which every MEX function requires. When you invoke a MEX function, MATLAB® finds and loads the corresponding MEX function of the same name. MATLAB then searches for a symbol named mexFunction within the MEX function. If it finds one, it calls the MEX function using the address of themexFunction symbol. MATLAB displays an error message if it cannot find a routine namedmexFunction inside the MEX function.
When you invoke a MEX function, MATLAB automatically seeds nlhs, plhs,nrhs, and prhs with the calling arguments. In the syntax of the MATLAB language, functions have the general form:
[a,b,c,...] = fun(d,e,f,...)
where the ... denotes more items of the same format. Thea,b,c... are left-side output arguments, and thed,e,f... are right-side input arguments. The argumentsnlhs and nrhs contain the number of left side and right side arguments, respectively. prhs is an array ofmxArray pointers whose length is nrhs.plhs is an array whose length is nlhs, where your function must set pointers for the output mxArrays.
Note
It is possible to return an output value even if nlhs = 0, which corresponds to returning the result in the ans variable.
To experiment with passing input arguments, build the mexfunction.c example, following the instructions inTables of MEX Function Source Code Examples.
Input Arguments
Number of expected mxArray output arguments, specified as an integer.
Array of pointers to the expected mxArray output arguments.
Number of input mxArrays, specified as an integer.
Array of pointers to the mxArray input arguments. Do not modify any prhs values in your MEX file. Changing the data in these read-only mxArrays can produce undesired side effects.
Examples
To open an example, type:
edit([fullfile(matlabroot,"extern","examples","mex","filename")]);
where filename is:
Version History
Introduced before R2006a