User`s manual

3 Creating Fortran MEX-Files

3-22

As this example shows, creating MEX-file gateways that handle multiple

inputs and outputs is straightforward. All you need to do is keep track of which

indices of the vectors

prhs and plhs correspond to which input and output

arguments of your function. In this example, the input variable

x corresponds

prhs(1) and the input variable y to prhs(2).

For an input scalar

x and a real 3-by-3 matrix,

x = 3; y = ones(3);

typing

z = xtimesy(x, y)

yields this result

z =

3 3 3

Handling Complex Data

MATLAB stores complex double-precision data as two vectors of numbers —

one contains the real data and one contains the imaginary data. The API

provides two functions,

mxCopyPtrToComplex16 and mxCopyComplex16ToPtr,

which allow you to copy the MATLAB data to a native

complex*16 Fortran

array.

This example takes two complex vectors (of length 3) and convolves them.

C $Revision: 1.14 $

C==============================================================

C convec.f

C Example for illustrating how to pass complex data from

C MATLAB to FORTRAN (using COMPLEX data type) and back

C again.

C Convolves two complex input vectors.

C This is a MEX-file for MATLAB.