virtual void SetUp() {
boxdim = 3;
nparticles = 1e1;
ndof = boxdim*nparticles;
origin = Array<double>(ndof);
std::fill(origin.data(),origin.data()+ndof,0);
x = Array<double>(ndof);
std::fill(x.data(),x.data()+ndof,0);
stepsize = 1e-2;
k = 400;
potential = std::make_shared<pele::Harmonic>(origin, k, boxdim);
max_iter = 1e5;
}
template<typename... Ix> arr data_t(const arr_t& a, Ix&&... index) {
return arr(a.size() - a.index_at(index...), a.data(index...));
}