STIN void dcsqf1(int n,float *x,float *w,float *xh,int *ifac){
int modn,i,k,kc;
int np2,ns2;
float xim1;
ns2=(n+1)>>1;
np2=n;
kc=np2;
for (k=1;k<ns2;k++){
kc--;
xh[k]=x[k]+x[kc];
xh[kc]=x[k]-x[kc];
}
modn=n%2;
if (modn==0)xh[ns2]=x[ns2]+x[ns2];
for (k=1;k<ns2;k++){
kc=np2-k;
x[k]=w[k-1]*xh[kc]+w[kc-1]*xh[k];
x[kc]=w[k-1]*xh[k]-w[kc-1]*xh[kc];
}
if (modn==0)x[ns2]=w[ns2-1]*xh[ns2];
__ogg_fdrfftf(n,x,xh,ifac);
for (i=2;i<n;i+=2){
xim1=x[i-1]-x[i];
x[i]=x[i-1]+x[i];
x[i-1]=xim1;
}
}
/**
* Calculates the Fast Fourier Transformation (FFT).
*/
void FastFourierTransformer::calculateFFT(QList<qint16> wave)
{
const int n = wave.size();
if (m_last_n != n) {
reserve(n);
}
for (int i = 0; i < n; i++) {
m_waveFloat[i] = (float) wave.at(i);
}
__ogg_fdrfftf(n, m_waveFloat, m_workingArray, m_ifac);
}
void
DiscreteFourierTransform(int n)
{
double p_value, upperBound, percentile, N_l, N_o, d, *m, *X, *wsave;
int i, count, ifac[15];
if ( ((X = (double*) calloc(n,sizeof(double))) == NULL) ||
((wsave = (double *)calloc(2*n,sizeof(double))) == NULL) ||
((m = (double*)calloc(n/2+1, sizeof(double))) == NULL) ) {
fprintf(stats[7],"\t\tUnable to allocate working arrays for the DFT.\n");
if( X == NULL )
free(X);
if( wsave == NULL )
free(wsave);
if( m == NULL )
free(m);
return;
}
for ( i=0; i<n; i++ )
X[i] = 2*(int)epsilon[i] - 1;
__ogg_fdrffti(n, wsave, ifac); /* INITIALIZE WORK ARRAYS */
__ogg_fdrfftf(n, X, wsave, ifac); /* APPLY FORWARD FFT */
m[0] = sqrt(X[0]*X[0]); /* COMPUTE MAGNITUDE */
for ( i=0; i<n/2; i++ )
m[i+1] = sqrt(pow(X[2*i+1],2)+pow(X[2*i+2],2));
count = 0; /* CONFIDENCE INTERVAL */
upperBound = sqrt(2.995732274*n);
for ( i=0; i<n/2; i++ )
if ( m[i] < upperBound )
count++;
percentile = (double)count/(n/2)*100;
N_l = (double) count; /* number of peaks less than h = sqrt(3*n) */
N_o = (double) 0.95*n/2.0;
d = (N_l - N_o)/sqrt(n/4.0*0.95*0.05);
p_value = erfc(fabs(d)/sqrt(2.0));
/*
printf("\t\t\t\tFFT TEST\n");
printf("\t\t-------------------------------------------\n");
printf("\t\tCOMPUTATIONAL INFORMATION:\n");
printf("\t\t-------------------------------------------\n");
printf("\t\t(a) Percentile = %f\n", percentile);
printf("\t\t(b) N_l = %f\n", N_l);
printf("\t\t(c) N_o = %f\n", N_o);
printf("\t\t(d) d = %f\n", d);
printf("\t\ttp_value = %f\n", p_value);
printf("\t\tstatus = %s\n", p_value < ALPHA ? "NON RANDOM" : "RANDOM");
printf("\t\t-------------------------------------------\n");
*/
fprintf(stats[TEST_FFT], "\t\t\t\tFFT TEST\n");
fprintf(stats[TEST_FFT], "\t\t-------------------------------------------\n");
fprintf(stats[TEST_FFT], "\t\tCOMPUTATIONAL INFORMATION:\n");
fprintf(stats[TEST_FFT], "\t\t-------------------------------------------\n");
fprintf(stats[TEST_FFT], "\t\t(a) Percentile = %f\n", percentile);
fprintf(stats[TEST_FFT], "\t\t(b) N_l = %f\n", N_l);
fprintf(stats[TEST_FFT], "\t\t(c) N_o = %f\n", N_o);
fprintf(stats[TEST_FFT], "\t\t(d) d = %f\n", d);
fprintf(stats[TEST_FFT], "\t\t-------------------------------------------\n");
fprintf(stats[TEST_FFT], "%s\t\tp_value = %f\n\n", p_value < ALPHA ? "FAILURE" : "SUCCESS", p_value);
fprintf(results[TEST_FFT], "%f\n", p_value);
free(X);
free(wsave);
free(m);
}