inline static
typename std::enable_if<ExpansionTraits<Expansion>::has_vector_P2M>::type
eval(const Expansion& K,
SourceIter s_begin, SourceIter s_end,
ChargeIter c_begin,
const typename Expansion::point_type& center,
typename Expansion::multipole_type& M) {
K.P2M(s_begin, s_end, c_begin, center, M);
}
inline static
typename std::enable_if<ExpansionTraits<Expansion>::has_scalar_P2M &
!ExpansionTraits<Expansion>::has_vector_P2M>::type
eval(const Expansion& K,
SourceIter s_begin, SourceIter s_end,
ChargeIter c_begin,
const typename Expansion::point_type& center,
typename Expansion::multipole_type& M) {
for ( ; s_begin != s_end; ++s_begin, ++c_begin)
K.P2M(*s_begin, *c_begin, center, M);
}
void two_level_test(const Expansion& K) {
typedef Expansion expansion_type;
typedef typename expansion_type::source_type source_type;
typedef typename expansion_type::target_type target_type;
typedef typename expansion_type::charge_type charge_type;
typedef typename expansion_type::result_type result_type;
typedef typename expansion_type::point_type point_type;
typedef typename expansion_type::multipole_type multipole_type;
typedef typename expansion_type::local_type local_type;
// init source
std::vector<source_type> s(1);
s[0] = source_type(0,0,0);
// init charge
std::vector<charge_type> c(1);
c[0] = charge_type(1);
// init target
std::vector<target_type> t(1);
t[0] = target_type(0.98,0.98,0.98);
// init results vectors for exact, FMM
std::vector<result_type> rexact(1);
result_type rm2p;
result_type rfmm;
// test direct
Direct::matvec(K, s, c, t, rexact);
// setup intial multipole expansion
multipole_type M;
point_type M_center(0.05, 0.05, 0.05);
point_type M_extent(0.1, 0.1, 0.1);
INITM::eval(K, M, M_extent, 2u);
K.P2M(s[0], c[0], M_center, M);
// perform M2M
multipole_type M2;
point_type M2_center(0.1, 0.1, 0.1);
point_type M2_extent(0.2, 0.2, 0.2);
INITM::eval(K, M2, M2_extent, 1u);
K.M2M(M, M2, M2_center - M_center);
//K.P2M(s,c,M2_center,M2);
// test M2P
K.M2P(M2, M2_center, t[0], rm2p);
// test M2L, L2P
#ifndef TREECODE_ONLY
local_type L2;
point_type L2_center(0.9, 0.9, 0.9);
point_type L2_extent(0.2, 0.2, 0.2);
INITL::eval(K, L2, L2_center, 1u);
K.M2L(M2, L2, L2_center - M2_center);
// test L2L
local_type L;
point_type L_center(0.95, 0.95, 0.95);
point_type L_extent(0.1, 0.1, 0.1);
INITL::eval(K, L, L_extent, 2u);
K.L2L(L2, L, L_center - L2_center);
// test L2P
K.L2P(L2, L2_center, t[0], rfmm);
#endif
// check errors
std::cout << "rexact = " << rexact[0] << std::endl;
std::cout << "rm2p = " << rm2p << "\n "
<< "[" << (rm2p - rexact[0]) << "]" << std::endl;
std::cout << "rfmm = " << rfmm << "\n "
<< "[" << (rfmm - rexact[0]) << "]" << std::endl;
}
