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dft_tools/triqs/gfs/product.hpp
Olivier Parcollet 7898bd8d88 gf : mesh now the class, not a trait.
simplify : mesh was a impl trait,
make it the class itself.
corrected the gf, tests and the cython.
2013-08-27 13:43:58 +02:00

175 lines
7.9 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2013 by O. Parcollet
*
* TRIQS is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* TRIQS. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#ifndef TRIQS_GF_PRODUCT_H
#define TRIQS_GF_PRODUCT_H
#include "./tools.hpp"
#include "./gf.hpp"
#include "./meshes/product.hpp"
namespace triqs { namespace gfs {
template<typename ... Ms> struct cartesian_product{
typedef std::tuple<Ms...> type;
static constexpr size_t size = sizeof...(Ms);
};
// the mesh is simply a cartesian product
template<typename Opt, typename ... Ms> struct mesh<cartesian_product<Ms...>,Opt> : mesh_product< mesh<Ms,Opt> ... > {
typedef mesh_product< mesh<Ms,Opt> ... > B;
typedef std::tuple<Ms...> mesh_name_t;
mesh (mesh<Ms,Opt> ... ms) : B {std::move(ms)...} {}
};
namespace gfs_implementation {
// h5 name : name1_x_name2_.....
template<typename Opt, typename ... Ms> struct h5_name<cartesian_product<Ms...>,matrix_valued,Opt> {
static std::string invoke(){
return triqs::tuple::fold(
[](std::string a, std::string b) { return a + std::string(b.empty()?"" : "_x_") + b;},
std::make_tuple(h5_name<Ms,matrix_valued,Opt>::invoke()...),
std::string());
}
};
/// --------------------------- data access ---------------------------------
template<typename Opt, typename ... Ms> struct data_proxy<cartesian_product<Ms...>,matrix_valued,Opt> : data_proxy_array<std::complex<double>,3> {};
template<typename Opt, typename ... Ms> struct data_proxy<cartesian_product<Ms...>,scalar_valued,Opt> : data_proxy_array<std::complex<double>,1> {};
/// --------------------------- evaluator ---------------------------------
struct evaluator_grid_simple {
size_t n;
evaluator_grid_simple() = default;
template<typename MeshType, typename PointType>
evaluator_grid_simple (MeshType const & m, PointType const & p) { n=p; }
template<typename F> auto operator()(F const & f) const DECL_AND_RETURN(f (n));
};
struct evaluator_grid_linear_interpolation {
double w1, w2; size_t n1, n2;
evaluator_grid_linear_interpolation() = default;
template<typename MeshType, typename PointType>
evaluator_grid_linear_interpolation (MeshType const & m, PointType const & p, double prefactor=1) { // delegate !
bool in; double w;
std::tie(in, n1, w) = windowing(m,p);
//std::cout << in << " "<< n1 << " "<< w << " " << p << std::endl;
if (!in) TRIQS_RUNTIME_ERROR <<" Evaluation out of bounds";
w1 = prefactor * w; w2 = prefactor *(1-w); n2 = n1 +1;
}
template<typename F> auto operator()(F const & f) const DECL_AND_RETURN(w1 * f(n1) + w2 * f (n2));
};
template<typename MeshType> struct evaluator_fnt_on_mesh;
// can not use inherited constructors, too recent...
#define TRIQS_INHERIT_AND_FORWARD_CONSTRUCTOR(NEWCLASS,CLASS) : CLASS { template<typename ...T> NEWCLASS(T &&... t) : CLASS(std::forward<T>(t)...){};};
template<> struct evaluator_fnt_on_mesh<imfreq> TRIQS_INHERIT_AND_FORWARD_CONSTRUCTOR(evaluator_fnt_on_mesh, evaluator_grid_simple);
template<> struct evaluator_fnt_on_mesh<imtime> TRIQS_INHERIT_AND_FORWARD_CONSTRUCTOR(evaluator_fnt_on_mesh, evaluator_grid_linear_interpolation);
template<> struct evaluator_fnt_on_mesh<retime> TRIQS_INHERIT_AND_FORWARD_CONSTRUCTOR(evaluator_fnt_on_mesh, evaluator_grid_linear_interpolation);
template<> struct evaluator_fnt_on_mesh<refreq> TRIQS_INHERIT_AND_FORWARD_CONSTRUCTOR(evaluator_fnt_on_mesh, evaluator_grid_linear_interpolation);
/**
* This the multi-dimensional evaluator.
* It combine the evaluator of each components, as long as they are a linear form
* eval(g, x) = \sum_i w_i g( n_i(x)) , with w some weight and n_i some points on the grid.
* Mathematically, it is written as (example of evaluating g(x1,x2,x3,x4)).
* Notation : eval(X) : g -> g(X)
* eval(x1,x2,x3,x4) (g) = eval (x1) ( binder ( g, (), (x2,x3,x4)) )
* binder( g, (), (x2,x3,x4)) (p1) = eval(x2)(binder (g,(p1),(x3,x4)))
* binder( g, (p1), (x3,x4)) (p2) = eval(x3)(binder (g,(p1,p2),(x4)))
* binder( g, (p1,p2), (x4)) (p3) = eval(x4)(binder (g,(p1,p2,p3),()))
* binder( g, (p1,p2,p3),()) (p4) = g[p1,p2,p3,p4]
*
* p_i are points on the grids, x_i points in the domain.
*
* Unrolling the formula gives (for 2 variables, with 2 points interpolation)
* eval(xa,xb) (g) = eval (xa) ( binder ( g, (), (xb)) ) = w_1(xa) binder ( g, (), (xb))( n_1(xa)) + w_2(xa) binder ( g, (), (xb))( n_2(xa))
* = w_1(xa) ( eval(xb)( binder ( g, (n_1(xa) ), ()))) + 1 <-> 2
* = w_1(xa) ( W_1(xb) * binder ( g, (n_1(xa) ), ())(N_1(xb)) + 1<->2 ) + 1 <-> 2
* = w_1(xa) ( W_1(xb) * g[n_1(xa), N_1(xb)] + 1<->2 ) + 1 <-> 2
* = w_1(xa) ( W_1(xb) * g[n_1(xa), N_1(xb)] + W_2(xb) * g[n_1(xa), N_2(xb)] ) + 1 <-> 2
* which is the expected formula
*/
// implementation : G = gf, Tn : tuple of n points, Ev : tuple of evaluators (the evals functions), pos = counter from #args-1 =>0
// NB : the tuple is build in reverse with respect to the previous comment.
template<typename G, typename Tn, typename Ev, int pos> struct binder;
template<int pos, typename G, typename Tn, typename Ev>
binder<G,Tn,Ev,pos> make_binder(G const * g, Tn tn, Ev const & ev) { return binder<G,Tn,Ev,pos>{g, std::move(tn), ev}; }
template<typename G, typename Tn, typename Ev, int pos> struct binder {
G const * g; Tn tn; Ev const & evals;
auto operator()(size_t p) const DECL_AND_RETURN( std::get<pos>(evals) ( make_binder<pos-1>(g, triqs::tuple::push_front(tn,p), evals) ));
};
template<typename G, typename Tn, typename Ev> struct binder<G,Tn,Ev,-1> {
G const * g; Tn tn; Ev const & evals;
auto operator()(size_t p) const DECL_AND_RETURN( triqs::tuple::apply(on_mesh(*g), triqs::tuple::push_front(tn,p)));
};
// now the multi d evaluator itself.
template<typename Target, typename Opt, typename ... Ms>
struct evaluator<cartesian_product<Ms...>,Target,Opt> {
static constexpr int arity = sizeof...(Ms);
mutable std::tuple< evaluator_fnt_on_mesh<Ms> ... > evals;
struct _poly_lambda {// replace by a polymorphic lambda in C++14
template<typename A, typename B, typename C> void operator()(A & a, B const & b, C const & c) const { a = A{b,c};}
};
template<typename G, typename ... Args>
std::complex<double> operator() (G const * g, Args && ... args) const {
static constexpr int R = sizeof...(Args);
// build the evaluators, as a tuple of ( evaluator<Ms> ( mesh_component, args))
triqs::tuple::call_on_zip(_poly_lambda(), evals, g->mesh().components(), std::make_tuple(args...));
return std::get<R-1>(evals) (make_binder<R-2> (g, std::make_tuple(), evals) );
}
};
// ------------------------------- Factories --------------------------------------------------
template<typename Opt, typename ... Ms>
struct factories<cartesian_product<Ms...>, scalar_valued,Opt> {
typedef gf<cartesian_product<Ms...>, scalar_valued,Opt> gf_t;
template<typename ... Meshes>
static gf_t make_gf(Meshes && ... meshes) {
auto m = mesh<cartesian_product<Ms...>,Opt>(meshes...);
typename gf_t::data_regular_t A(m.size());
A() =0;
return gf_t (m, std::move(A), nothing(), nothing());
}
};
} // gf_implementation
}}
#endif