MATLAB^®

mexFunction (C and Fortran) - Entry point to C MEX-file

C Syntax

#include "mex.h"
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, 
     const mxArray *prhs[]);

Fortran Syntax

mexFunction(nlhs, plhs, nrhs, prhs)
integer*4 nlhs, nrhs
mwPointer plhs(*), prhs(*)

Arguments

nlhs: The number of expected output mxArrays
plhs: Array of pointers to the expected output mxArrays
nrhs: The number of input mxArrays
prhs: Array of pointers to the input mxArrays. These mxArrays are read only and should not be modified by your MEX-file. Changing the data in these mxArrays may produce undesired side effects.

Description

mexFunction is not a routine you call. Rather, mexFunction is the name of a function in C (subroutine in Fortran) that you must write in every MEX-file. When you invoke a MEX-function, MATLAB software finds and loads the corresponding MEX-file of the same name. MATLAB then searches for a symbol named mexFunction within the MEX-file. If it finds one, it calls the MEX-function using the address of the mexFunction symbol. If MATLAB cannot find a routine named mexFunction inside the MEX-file, it issues an error message.

When you invoke a MEX-file, MATLAB automatically seeds nlhs, plhs, nrhs, and prhs with the caller's information. 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. The a,b,c... are left-hand side arguments, and the d,e,f... are right-hand side arguments. The arguments nlhs and nrhs contain the number of left-hand side and right-hand side arguments, respectively, with which the MEX-function is called. prhs is an array of mxArray pointers whose length is nrhs. plhs is an array whose length is nlhs, where your function must set pointers for the returned left-hand side mxArrays.

C Examples

See mexfunction.c in the mex subdirectory of the examples directory.

mexEvalStringWithTrap (C and Fortran)

mexFunctionName (C and Fortran)

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