static double verify_impulse(fftd_func *dft,
int n, int veclen,
COMPLEX *inA,
COMPLEX *inB,
COMPLEX *inC,
COMPLEX *outA,
COMPLEX *outB,
COMPLEX *outC,
COMPLEX *tmp,
int rounds)
{
int N = n * veclen;
COMPLEX impulse;
int i;
double e, maxerr = 0.0;
/* test 2: check that the unit impulse is transformed properly */
RE(impulse) = 1.0;
IM(impulse) = 0.0;
for (i = 0; i < N; ++i) {
/* impulse */
RE(inA[i]) = 0.0;
IM(inA[i]) = 0.0;
/* transform of the impulse */
outA[i] = impulse;
}
for (i = 0; i < veclen; ++i)
inA[i * n] = impulse;
/* a simple test first, to help with debugging: */
dft((double *)outB, (double *)inA);
e = acmp(outB, outA, N);
if(e > maxerr) maxerr = e;
for (i = 0; i < rounds; ++i) {
fill_random(inB, N);
asub(inC, inA, inB, N);
dft((double *)outB, (double *)inB);
dft((double *)outC, (double *)inC);
aadd(tmp, outB, outC, N);
e = acmp(tmp, outA, N);
if(e > maxerr) maxerr = e;
}
return maxerr;
}
static double impulse0(dofft_closure *k,
int n, int vecn,
C *inA, C *inB, C *inC,
C *outA, C *outB, C *outC,
C *tmp, int rounds, double tol)
{
int N = n * vecn;
double e = 0.0;
int j;
k->apply(k, inA, tmp);
e = dmax(e, acmp(tmp, outA, N, "impulse 1", tol));
for (j = 0; j < rounds; ++j) {
arand(inB, N);
asub(inC, inA, inB, N);
k->apply(k, inB, outB);
k->apply(k, inC, outC);
aadd(tmp, outB, outC, N);
e = dmax(e, acmp(tmp, outA, N, "impulse", tol));
}
return e;
}
