User`s manual

3 Creating Fortran MEX-Files

3-6

The Gateway Routine

The entry point to the gateway subroutine must be named mexFunction and

must contain these parameters.

subroutine mexFunction(nlhs, plhs, nrhs, prhs)

integer plhs(*), prhs(*)

integer nlhs, nrhs

Note Fortran is case-insensitive. This document uses mixed-case function

names for ease of reading.

In a Fortran MEX-file, the parameters

nlhs and nrhs contain the number of

left- and right-hand arguments with which the MEX-file is invoked.

prhs is a

length

nrhs array that contains pointers to the right-hand side inputs to the

MEX-file, and

plhs is a length nlhs array that contains pointers to the

left-hand side outputs that your Fortran function generates.

In the syntax of the MATLAB language, functions have the general form

[a,b,c,…] = fun(d,e,f,…)

where the ellipsis (…) denotes additional terms of the same format. The a,b,c,…

are left-hand arguments and the

d,e,f,… are right-hand arguments.

As an example of the gateway routine, consider invoking a MEX-file from the

MATLAB workspace with the command

x = fun(y,z);

the MATLAB interpreter calls mexFunction with the arguments

nlhs = 1

nrhs = 2

plhs

prhs

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