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clef: first version of generic sum function

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- to improve with in the case where function return an expression
  template, not a regular type, with a make_regular function
This commit is contained in:
Olivier Parcollet 2014-04-04 17:47:21 +02:00
parent 9762b95936
commit efb00ea5d3
4 changed files with 58 additions and 5 deletions
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21
test/triqs/clef_examples/sum3.cpp Normal file
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@ -0,0 +1,21 @@
#include <triqs/arrays.hpp>
/// ---- test ------------
using triqs::arrays::range;
int main() {
triqs::clef::placeholder<0> a_;
triqs::clef::placeholder<1> i_;
triqs::clef::placeholder<2> j_;
auto expr = i_ + 2* j_;
auto xa = sum(a_*i_ , i_=range(0,5));
auto x = eval(xa, a_=2);
std::cout << x << std::endl;
auto y = sum(2*i_ + j_ , i_=range(0,3), j_= range (0,2));
std::cout << y << std::endl;
}

10
test/triqs/gfs/g_k_om2.cpp
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@ -11,8 +11,8 @@ using namespace triqs::arrays;
using namespace triqs::lattice;
template <typename Function, typename Mesh>
// requires ( is_function_on_mesh<Function,Mesh>())
auto sum(Function const &f, Mesh const &m) ->decltype(make_matrix(0*f(*(m.begin())))) {
//auto sum(Function const &f, Mesh const &m) {
auto sum_gf(Function const &f, Mesh const &m) ->decltype(make_matrix(0*f(*(m.begin())))) {
//auto sum_gf(Function const &f, Mesh const &m) {
//auto res = typename triqs::regular_type_if_exists_else_type<decltype(f(typename Mesh::mesh_point_t{}))>::type (f(m.begin()));
auto res = make_matrix(0*f(*(m.begin())));
for (auto const &x : m) res = res + f(x);
@ -20,7 +20,7 @@ auto sum(Function const &f, Mesh const &m) ->decltype(make_matrix(0*f(*(m.begin
}
namespace triqs {
namespace clef {
TRIQS_CLEF_MAKE_FNT_LAZY(sum);
TRIQS_CLEF_MAKE_FNT_LAZY(sum_gf);
TRIQS_CLEF_MAKE_FNT_LAZY(conj);
}
}
@ -49,8 +49,8 @@ int main() {
auto r = G_k_iom(k_t{0, 0}, matsubara_freq{0, beta, Fermion});
auto r5 = sum(k_ >> G_k_iom(k_,0), g_eps.mesh());
G_loc(w_) << sum(k_ >> G_k_iom(k_,w_), g_eps.mesh());
auto r5 = sum_gf(k_ >> G_k_iom(k_,0), g_eps.mesh());
G_loc(w_) << sum_gf(k_ >> G_k_iom(k_,w_), g_eps.mesh());
TEST(G_loc(0));

6
triqs/arrays/indexmaps/range.hpp
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@ -76,6 +76,12 @@ namespace arrays {
const_iterator cend() const { return const_iterator(this, true); }
};
// foreach
template <typename F> void foreach(range const& r, F const& f) {
std::ptrdiff_t i = r.first(), last = r.last(), step = r.step();
for (; i < last; i += step) f(i);
}
/**
*/
class ellipsis : public range {

26
triqs/clef/clef.hpp
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@ -585,5 +585,31 @@ namespace triqs { namespace clef {
\
template <typename... Args> \
auto operator()(Args&&... args) && DECL_AND_RETURN(make_expr_call(std::move(*this), std::forward<Args>(args)...));
/* --------------------------------------------------------------------------------------------------
* sum of expressions
* --------------------------------------------------------------------------------------------------- */
// sum a function f on a domain D, using a simple foreach
template <typename F, typename D>
auto sum_f_domain_impl(F const& f, D const& d)
-> std::c14::enable_if_t<!triqs::clef::is_any_lazy<F, D>::value, decltype(f(*(d.begin())))> {
auto res = decltype(f(*(d.begin()))) {};
using p_t = typename std::decay<decltype(*(d.begin()))>::type;
foreach(d, [&res, &f](p_t const& x) { res = res + f(x); });
return res;
}
TRIQS_CLEF_MAKE_FNT_LAZY(sum_f_domain_impl);
// sum( expression, i = domain)
template <typename Expr, int N, typename D> auto sum(Expr const& f, clef::pair<N, D> const& d)
DECL_AND_RETURN(sum_f_domain_impl(make_function(f, clef::placeholder<N>()), d.rhs));
// two or more indices : sum recursively
template <typename Expr, typename D0, int N0, typename D1, int N1, typename... D, int... N>
auto sum(Expr const& f, clef::pair<N0, D0> const& d0, clef::pair<N1, D1> const& d1, clef::pair<N, D> const&... d)
DECL_AND_RETURN(sum(sum(f, d0), d1, d...));
}} // namespace triqs::clef
#endif