Matlab coder C conversion of an fft

Can someone give me an example of what an fft should look like within a coder converted c code snippet? I am aware that the documentation says that fft is coder compatible, but I have not yet obtained successful results. What I end up receiving from coder is simply a copy of the input data. any help would be welcome. An example of what I have been testing is below.

function anFFT= fft_soundfile(input)
anFFT = input;
%do fft
X = abs(fft(input,1024));
%fft end
holder = X(1);
%data = abs(y)
end

What I am getting is as follows

/*
 * Academic License - for use in teaching, academic research, and meeting
 * course requirements at degree granting institutions only.  Not for
 * government, commercial, or other organizational use.
 *
 * anFFT.c
 *
 * Code generation for function 'anFFT'
 *
 */

/* Include files */
#include "rt_nonfinite.h"
#include "anFFT.h"

/* Function Definitions */
void anFFT(const double input[27387], double b_anFFT[27387])
{
  memcpy(&b_anFFT[0], &input[0], 27387U * sizeof(double));

    /* do fft */
    /* fft end */
    /* data = abs(y) */
  }

/* End of code generation (anFFT.c) */

This doesn't seem to be generating an fft. Can anyone help with this?

Answer 1

[Walter Roberson]

You have

function anFFT= fft_soundfile(input)
anFFT = input;

so your output is a copy of your input. Nothing you do later in your code affects the output. Everything after that point is optimized away.

[Tommy Owens]

Thank you, as you can probably tell with this mistake; I am new to using MATLAB. That easily fixed my problem.