int main()
{
int n, ip[NMAXSQRT + 2];
double a[NMAX + 1], w[NMAX * 5 / 4], t[NMAX / 2 + 1], err;
printf("data length n=? (must be 2^m)\n");
scanf("%d", &n);
ip[0] = 0;
/* check of CDFT */
putdata(0, n - 1, a);
cdft(n, 1, a, ip, w);
cdft(n, -1, a, ip, w);
err = errorcheck(0, n - 1, 2.0 / n, a);
printf("cdft err= %g \n", err);
/* check of RDFT */
putdata(0, n - 1, a);
rdft(n, 1, a, ip, w);
rdft(n, -1, a, ip, w);
err = errorcheck(0, n - 1, 2.0 / n, a);
printf("rdft err= %g \n", err);
/* check of DDCT */
putdata(0, n - 1, a);
ddct(n, 1, a, ip, w);
ddct(n, -1, a, ip, w);
a[0] *= 0.5;
err = errorcheck(0, n - 1, 2.0 / n, a);
printf("ddct err= %g \n", err);
/* check of DDST */
putdata(0, n - 1, a);
ddst(n, 1, a, ip, w);
ddst(n, -1, a, ip, w);
a[0] *= 0.5;
err = errorcheck(0, n - 1, 2.0 / n, a);
printf("ddst err= %g \n", err);
/* check of DFCT */
putdata(0, n, a);
a[0] *= 0.5;
a[n] *= 0.5;
dfct(n, a, t, ip, w);
a[0] *= 0.5;
a[n] *= 0.5;
dfct(n, a, t, ip, w);
err = errorcheck(0, n, 2.0 / n, a);
printf("dfct err= %g \n", err);
/* check of DFST */
putdata(1, n - 1, a);
dfst(n, a, t, ip, w);
dfst(n, a, t, ip, w);
err = errorcheck(1, n - 1, 2.0 / n, a);
printf("dfst err= %g \n", err);
return 0;
}
// compute distances from rows of inmat1 to rows of inmat2
RcppExport SEXP rthpdist(SEXP inmat1,SEXP inmat2, SEXP nthreads)
{
Rcpp::NumericMatrix im1(inmat1);
Rcpp::NumericMatrix im2(inmat2);
int nr1 = im1.nrow();
int nc = im1.ncol();
int nr2 = im2.nrow();
#if RTH_OMP
omp_set_num_threads(INT(nthreads));
#elif RTH_TBB
// tbb::task_scheduler_init init(INT(nthreads));
// for unknown reasons, this code does not work under TBB
return Rcpp::wrap(-1);
#endif
thrust::device_vector<double> dmat1(im1.begin(),im1.end());
thrust::device_vector<double> dmat2(im2.begin(),im2.end());
// make space for the output
thrust::device_vector<double> ddst(nr1*nr2);
// iterators for row number of inmat1
thrust::counting_iterator<int> iseqb(0);
thrust::counting_iterator<int> iseqe = iseqb + nr1;
// for each i in [iseqb,iseqe) find the distances from row i in inmat1
// to all rows of inmat2
thrust::for_each(iseqb,iseqe,
do1ival(dmat1.begin(),dmat2.begin(),ddst.begin(),nr1,nc,nr2));
Rcpp::NumericMatrix rout(nr1,nr2);
thrust::copy(ddst.begin(),ddst.end(),rout.begin());
return rout;
}
void DoFFT()
{
// SampleBuffer に高速離散フーリエ変換 (実際はサイン変換) を行い
// FFTData に格納する
tjs_int len = SampleBufferLen;
tjs_int len2 = len / 2;
if(FFTLen != len)
{
FFTLen = len;
// バッファの確保
if(FFTData) delete [] FFTData, FFTData = NULL;
if(WindowData) delete [] WindowData, WindowData = NULL;
if(fft_ip) delete [] fft_ip, fft_ip = NULL;
if(fft_w) delete[] fft_w, fft_w = NULL;
FFTData = new float[len];
WindowData = new float[len];
fft_ip = new int[(int)(2.0 + sqrt(len * (1.0 / 2.0)))];
fft_w = new float[(int)(len * (5.0 / 4.0))];
fft_ip[0] = 0;
// 窓関数の作成
float mul = (4.0/32768.0/len);
for(tjs_int i = 0; i < len; i++)
{
WindowData[i] = sin(3.14159265358979 * (i + 0.5) / len) * mul;
// (sin窓)
}
}
// FFTData に窓関数を適用しながらデータを転送
for(tjs_int i = 0; i < len2; i++)
{
FFTData[i] = SampleBuffer[i] * WindowData[i];
FFTData[i + len2] = SampleBuffer[i + len2] * WindowData[len2 - i - 1];
}
// 高速離散サイン変換
ddst(len, -1, FFTData, fft_ip, fft_w);
// 直流成分のカット
FFTData[0] = FFTData[1] = 0;
}
void dfst(int n, double *a)
{
void ddst(int n, int isgn, double *a);
void bitrv1(int n, double *a);
int j, k, m, mh;
double xr, xi, yr, yi;
m = n >> 1;
for (j = 1; j < m; j++) {
k = n - j;
xr = a[j] - a[k];
a[j] += a[k];
a[k] = xr;
}
a[0] = a[m];
while (m >= 2) {
ddst(m, 1, a);
bitrv1(m, a);
mh = m >> 1;
for (j = 1; j < mh; j++) {
k = m - j;
xr = a[m + k];
xi = a[m + j];
yr = a[j];
yi = a[k];
a[m + j] = yr;
a[m + k] = yi;
a[j] = xr + xi;
a[k] = xr - xi;
}
a[m] = a[0];
a[0] = a[m + mh];
a[m + mh] = a[mh];
m = mh;
}
a[1] = a[0];
a[0] = 0;
bitrv1(n, a);
}
