mexFunction (External Interfaces/API Reference)

MATLAB entry point to a Fortran MEX-file

Fortran Syntax

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

Arguments

nlhs
The number of expected outputs.

plhs
Array of pointers to expected outputs.

nrhs
The number of inputs.

prhs
Array of pointers to input data. The input data is read only and should not be altered by your mexFunction.

Description

mexFunction is not a routine you call. Rather, mexFunction is the name of a subroutine you must write in every MEX-file. When you invoke a MEX-file, MATLAB searches for a subroutine named mexFunction inside the MEX-file. If it finds one, then the first executable line in mexFunction becomes the starting point of the MEX-file. If MATLAB cannot find a subroutine named mexFunction inside the MEX-file, MATLAB issues an error message.

When you invoke a MEX-file, MATLAB automatically loads 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-file is called. prhs is an array of mxArray pointers whose length is nrhs. plhs is a pointer to an array whose length is nlhs, where your function must set pointers for the returned left-hand side mxArrays.

mexEvalString mexFunctionName