C++ (Cpp) fft_create_plan_r2r_1d Examples

Example #1

File: fft_r2r_autotest.c Project: 0xLeo/liquid-dsp

// autotest helper function
void fft_r2r_test(float *      _x,
                  float *      _test,
                  unsigned int _n,
                  unsigned int _kind)
{
    int _flags = 0;
    float tol=1e-4f;

    unsigned int i;

    float y[_n];

    // compute real even/odd FFT
    fftplan q = fft_create_plan_r2r_1d(_n, _x, y, _kind, _flags);
    fft_execute(q);

    // print results
    if (liquid_autotest_verbose) {
        printf("%12s %12s\n", "expected", "actual");
        for (i=0; i<_n; i++)
            printf("%12.8f %12.8f\n", _test[i], y[i]);
    }

    // validate results
    for (i=0; i<_n; i++)
        CONTEND_DELTA( y[i], _test[i], tol);

    // destroy plans
    fft_destroy_plan(q);
}

Example #2

File: fft_r2r_benchmark.c Project: shishougang/liquid-dsp

// Helper function to keep code base small
void fft_r2r_bench(struct rusage *_start,
                   struct rusage *_finish,
                   unsigned long int *_num_iterations,
                   unsigned int _n,
                   int _kind)
{
    // initialize arrays, plan
    float x[_n], y[_n];
    int _flags = 0;
    fftplan p = fft_create_plan_r2r_1d(_n, x, y, _kind, _flags);
    
    unsigned long int i;

    // initialize input with random values
    for (i=0; i<_n; i++)
        x[i] = randnf();

    // scale number of iterations to keep execution time
    // relatively linear
    *_num_iterations /= _n * _n;
    *_num_iterations *= 10;
    *_num_iterations += 1;

    // start trials
    getrusage(RUSAGE_SELF, _start);
    for (i=0; i<(*_num_iterations); i++) {
        fft_execute(p);
        fft_execute(p);
        fft_execute(p);
        fft_execute(p);
    }
    getrusage(RUSAGE_SELF, _finish);
    *_num_iterations *= 4;

    fft_destroy_plan(p);
}