arma_hot
inline
void
butterfly_N(cx_type* Y, const uword stride, const uword m, const uword r)
{
arma_extra_debug_sigprint();
const cx_type* coeffs = coeffs_ptr();
tmp_array.set_min_size(r);
cx_type* tmp = tmp_array.memptr();
for(uword u=0; u < m; ++u)
{
uword k = u;
for(uword v=0; v < r; ++v)
{
tmp[v] = Y[k];
k += m;
}
k = u;
for(uword v=0; v < r; ++v)
{
Y[k] = tmp[0];
uword j = 0;
for(uword w=1; w < r; ++w)
{
j += stride * k;
if(j >= N) { j -= N; }
Y[k] += tmp[w] * coeffs[j];
}
k += m;
}
}
}
inline
podarray<eT>::podarray(const podarray& x)
: n_elem(x.n_elem)
{
arma_extra_debug_sigprint();
const uword x_n_elem = x.n_elem;
init_cold(x_n_elem);
arrayops::copy( memptr(), x.memptr(), x_n_elem );
}
inline
fft_engine(const uword in_N)
: store< cx_type, fixed_N, (fixed_N > 0) >(in_N)
{
arma_extra_debug_sigprint();
const uword len = calc_radix<false>();
residue.set_size(len);
radix.set_size(len);
calc_radix<true>();
// calculate the constant coefficients
cx_type* coeffs = coeffs_ptr();
const T k = T( (inverse) ? +2 : -2 ) * std::acos( T(-1) ) / T(N);
for(uword i=0; i < N; ++i) { coeffs[i] = std::exp( cx_type(T(0), i*k) ); }
}
inline
const podarray<eT>&
podarray<eT>::operator=(const podarray& x)
{
arma_extra_debug_sigprint();
if(this != &x)
{
const uword x_n_elem = x.n_elem;
init_warm(x_n_elem);
arrayops::copy( memptr(), x.memptr(), x_n_elem );
}
return *this;
}
arma_inline cx_type* coeffs_ptr() { return coeffs_array.memptr(); }
inline store(uword in_N) : N(in_N) { coeffs_array.set_size(N); }
