void KTable::accumulate(const KTable& rhs, double scalar)
{
clearCache(); // invalidate any stored interpolations
check_array();
if (_N != rhs._N) throw FFTError("KTable::accumulate() with mismatched sizes");
if (_dk != rhs._dk) throw FFTError("KTable::accumulate() with mismatched dk");
for (int i=0; i<_N*(_No2+1); ++i)
_array[i] += scalar * rhs._array[i];
}
void KTable::operator*=(const KTable& rhs)
{
clearCache(); // invalidate any stored interpolations
check_array();
if (_N != rhs._N) throw FFTError("KTable::operator*=() with mismatched sizes");
if (_dk != rhs._dk) throw FFTError("KTable::operator*=() with mismatched dk");
for (int i=0; i<_N*(_No2+1); ++i)
_array[i] *= rhs._array[i];
}
XTable::XTable(int N, double dx, double value) : _dx(dx)
{
#ifdef FFT_DEBUG
if (N<=0) throw FFTError("XTable size <=0");
#endif
_N = 2*((N+1)/2); //Round size up to even.
_array.resize(_N);
_array.fill(value);
}
void XTable::accumulate(const XTable& rhs, double scalar)
{
check_array();
clearCache(); // invalidate any stored interpolations
#ifdef FFT_DEBUG
if (_N != rhs._N) throw FFTError("XTable::accumulate() with mismatched sizes");
#endif
for (int i=0; i<_N*_N; i++)
_array[i] += scalar * rhs._array[i];
}
void TestDft()
{
// icomplex v[82];
// icomplex w[82];
// ComputeFFT80RtoCCosSinTable();
// ComputeFFT16RtoCCosSinTable();
rngseed = 1; // Seed random number generator.
#if (0)
printf("testing FFT80CtoC() as its own inverse (with conjugation)\n");
// compute_dft5_constants();
// compute_dft16_constants();
getdft80tables(); // Initialize 3 tables used in fast 80-pt FFT.
// compute_dBTable();
total_err_db = 0;
#define NUM_TESTS 64
for (k=0; k<NUM_TESTS; k++)
{
for (j=0; j<80; j++) {
w[j].r = myrand();
v[j].r = w[j].r;
}
for (j=0; j<80; j++) {
w[j].i = myrand();
v[j].i = w[j].i;
}
// DEBUG!!! Also test with sine waves.
/* for (j=0; j<80; j++) {
printf("%6d %6d ",w[j].r,w[j].i);
if ((j%4) == 3) printf("\n");
}
getchar(); */
// FFT80CtoC() scales up by square root of 80.
// Here, we scale down the first output by 8 and the second output by 10.
FFT80CtoC(v);
for (i=0; i < 80; i++) {
v[i].r = (v[i].r + 4) >> 3;
v[i].i = (-v[i].i + 4) >> 3;
}
FFT80CtoC(v);
for (i=0; i < 80; i++) {
v[i].r = (v[i].r * 3277 + 16384) >> 15;
v[i].i = (-v[i].i * 3277 + 16384) >> 15;
}
/* for (i=0; i < 80; i++) {
printf("%6d %6d %6d %6d\n",w[i].r, w[i].i,
v[i].r, v[i].i);
if (i%16 == 15) getchar();
}
getchar(); */
total_err_db += FFTError((int *) v,(int *) w, 2*80);
// if (k%4 == 3) printf("\n");
printf("\n");
}
printf("\n");
total_err_db /= NUM_TESTS;
printf("average error is %2d.%2d dB down.\n",total_err_db/100,
total_err_db - (total_err_db/100)*100);
// printf("average error should be 66.17 db down.\n");
getchar();
#endif
#if (0)
printf("testing FFT40CtoC() as its own inverse (with conjugation)\n");
GetDft40Tables(); // Initialize 3 tables used in fast 40-pt FFT.
total_err_db = 0;
#define NUM_TESTS 64
for (k=0; k<NUM_TESTS; k++)
{
for (j=0; j<40; j++) {
w[j].r = myrand();
v[j].r = w[j].r;
}
for (j=0; j<40; j++) {
w[j].i = myrand();
v[j].i = w[j].i;
}
// DEBUG!!! Also test with sine waves.
/* for (j=0; j<40; j++) {
printf("%6d %6d ",w[j].r,w[j].i);
if ((j%4) == 3) printf("\n");
}
getchar(); */
// FFT40CtoC() scales up by square root of 40.
// Here, we scale down the first output by 4 and the second output by 10.
FFT40CtoC(v);
for (i=0; i < 40; i++) {
v[i].r = (v[i].r + 2) >> 2;
v[i].i = (-v[i].i + 2) >> 2;
}
FFT40CtoC(v);
for (i=0; i < 40; i++) {
v[i].r = (v[i].r * 3277 + 16384) >> 15;
v[i].i = (-v[i].i * 3277 + 16384) >> 15;
}
/* for (i=0; i < 40; i++) {
printf("%6d %6d %6d %6d\n",w[i].r, w[i].i,
v[i].r, v[i].i);
if (i%16 == 15) getchar();
}
getchar(); */
total_err_db += FFTError((int *) v,(int *) w, 2*40);
if (k%8 == 7) printf("\n");
// printf("\n");
}
printf("\n");
total_err_db /= NUM_TESTS;
printf("average error is %2d.%2d dB down.\n",total_err_db/100,
total_err_db - (total_err_db/100)*100);
printf("average error should be 68.54 db down.\n");
getchar();
#endif
#if (0)
printf("testing FFT80RtoC() vs FFT80CtoC()\n");
int x[82];
getdft80tables(); // Initialize 3 tables used in fast 80-pt FFT
total_err_db = 0;
for (k=0; k<64; k++)
{
for (j=0; j < 80; j++)
{
x[j]= myrand();
v[j].r = x[j];
v[j].i = 0;
}
FFT80RtoC((icomplex *) x);
for (i=0; i <= 40; i++) {
w[i].r = x[2*i];
w[i].i = x[2*i+1];
}
FFT80CtoC(v);
/*
for (i=0; i <= 40; i++) {
printf("%6d %6d %6d %6d %6d %6d\n",v[i].r, v[i].i,
w[i].r, w[i].i, (v[i].r - w[i].r), (v[i].i - w[i].i));
if (i%16 == 15) getchar();
}
getchar();
*/
total_err_db += FFTError((int *) w,(int *) v, 2*41);
// if (k%4 == 3) printf("\n");
printf("\n");
}
printf("\n");
total_err_db /= 64;
printf("average error is %2d.%2d dB down.\n",total_err_db/100,
total_err_db - (total_err_db/100)*100);
getchar();
#endif
#if (0)
printf("testing FFT80CtoR() vs FFT80CtoC()\n");
icomplex u[41];
int x[80];
total_err_db = 0;
for (k=0; k<64; k++)
{
for (j=0; j <= 40; j++)
{
u[j].r = myrand();
u[j].i = myrand();
}
u[0].i = 0;
u[40].i = 0;
for (j=0; j <= 40; j++)
{
v[j].r = u[j].r;
v[j].i = -u[j].i;
}
for (j=1; j < 40; j++)
{
v[80-j].r = u[j].r;
v[80-j].i = u[j].i;
}
FFT80CtoR(x,u);
FFT80CtoC(v);
for (i=0; i < 80; i++) {
printf("%6d %6d %6d %6d\n",v[i].r, v[i].i,
x[i], (v[i].r - x[i]));
if (i%16 == 15) getchar();
}
getchar();
double pow,err,dif;
pow = 0.0;
err = 0.0;
for (i=0; i<80; i++) {
pow += (v[i].r * v[i].r);
dif = (x[i] - v[i].r);
err += dif*dif;
}
printf("%8.2f ",10.0*log10(pow/err));
// getchar();
}
#endif
#if (0)
printf("testing FFT80RtoC() and FFT80CtoR() as inverses\n");
int x[80];
int y[82];
total_err_db = 0;
#define NUM_TESTS 64
for (k=0; k<NUM_TESTS; k++)
{
for (j=0; j < 80; j++)
{
x[j]= myrand();
y[j] = x[j];
}
FFT80RtoC((icomplex *) y);
// FFT80RtoC() and FFT80CtoR() each scale up by square root of 80.
// Here, we scale down the first output by 8 and the second output by 10.
// How we do the scaling here can have a huge effect on measured error.
for (i=0; i < 82; i++) {
y[i] = (y[i] + 4) >> 3;
}
FFT80CtoR((icomplex *) y);
for (i=0; i < 80; i++) {
y[i] = (y[i] * 3277 + 16384) >> 15;
}
// xxx
/* for (i=0; i < 80; i++) {
printf("%6d %6d ",x[i], y[i]);
if (i%4 == 3) printf("\n");
}
getchar(); */
total_err_db += FFTError(x, y, 80);
// getchar();
if (k%8 == 7) printf("\n");
// printf("\n");
}
// printf("\n");
total_err_db /= NUM_TESTS;
printf("average error is %2d.%2d dB down.\n",total_err_db/100,
total_err_db - (total_err_db/100)*100);
printf("average error should be 64.08 db down.\n");
getchar();
#endif
#if (0)
printf("testing FFT16RtoC() vs FFT16CtoC()\n");
int x[18];
total_err_db = 0;
for (k=0; k<64; k++)
{
for (j=0; j < 16; j++)
{
x[j]= myrand();
v[j].r = x[j];
v[j].i = 0;
}
FFT16RtoC((icomplex *) x);
for (i=0; i <= 8; i++) {
w[i].r = x[2*i];
w[i].i = x[2*i+1];
}
FFT16CtoC(v);
for (i=0; i <= 8; i++) {
printf("%6d %6d %6d %6d %6d %6d\n",v[i].r, v[i].i,
w[i].r, w[i].i, (v[i].r - w[i].r), (v[i].i - w[i].i));
}
getchar();
total_err_db += FFTError((int *) w,(int *) v, 2*9);
// if (k%4 == 3) printf("\n");
printf("\n");
}
printf("\n");
total_err_db /= 64;
printf("average error is %2d.%2d dB down.\n",total_err_db/100,
total_err_db - (total_err_db/100)*100);
getchar();
#endif
#if (VX1_PC0 == 0)
#if (0)
printf("testing FFT16RtoC() and FFT16CtoR() as inverses\n");
int x[16];
int y[18];
total_err_db = 0;
#define NUM_TESTS 64
for (k=0; k<NUM_TESTS; k++)
{
for (j=0; j < 16; j++)
{
x[j]= myrand();
y[j] = x[j];
}
FFT16RtoC((icomplex *) y);
// FFT80RtoC() and FFT80CtoR() each scale up by square root of 16.
// Here, we scale down the first output by 2 and the second output by 2.
// How we do the scaling here can have a huge effect on measured error.
for (i=0; i < 18; i++) {
y[i] = (y[i] + 2) >> 2;
}
FFT16CtoR((icomplex *) y);
for (i=0; i < 16; i++) {
y[i] = (y[i] + 2) >> 2;
}
// xxx
/* for (i=0; i < 16; i++) {
printf("%6d %6d ",x[i], y[i]);
if (i%4 == 3) printf("\n");
}
getchar(); */
total_err_db += FFTError(x, y, 16);
// getchar();
if (k%8 == 7) printf("\n");
// printf("\n");
}
// printf("\n");
total_err_db /= NUM_TESTS;
printf("average error is %2d.%2d dB down.\n",total_err_db/100,
total_err_db - (total_err_db/100)*100);
// printf("average error should be 64.08 db down.\n");
getchar();
#endif
#endif
}
