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dft_tools/triqs/gfs/meshes/linear.hpp
2013-09-09 15:41:46 +02:00

206 lines
7.6 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2012 by M. Ferrero, 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_MESH_LINEAR_H
#define TRIQS_GF_MESH_LINEAR_H
#include "./mesh_tools.hpp"
// ADDED for Krylov : to be clean and removed if necessary
#include <algorithm>
#include <boost/math/special_functions/round.hpp>
namespace triqs { namespace gfs {
// Three possible meshes
enum mesh_kind { half_bins, full_bins, without_last };
template<typename Domain>
struct linear_mesh {
typedef Domain domain_t;
typedef size_t index_t;
typedef typename domain_t::point_t domain_pt_t;
linear_mesh () : _dom(), L(0), a_pt(0), b_pt(0), xmin(0), xmax(0), del(0), meshk(half_bins) {}
linear_mesh (domain_t const & dom, double a, double b, size_t n_pts, mesh_kind mk) :
_dom(dom), L(n_pts), a_pt(a), b_pt(b), meshk(mk) {
switch(mk) {
case half_bins: del = (b-a)/L; xmin = a+0.5*del; break;
case full_bins: del = (b-a)/(L-1); xmin = a; break;
case without_last: del = (b-a)/L; xmin = a; break;
}
xmax = xmin + del*(L-1);
}
linear_mesh (domain_t && dom, double a, double b, size_t n_pts, mesh_kind mk) :
_dom(dom), L(n_pts), a_pt(a), b_pt(b), meshk(mk) {
switch(mk) {
case half_bins: del = (b-a)/L; xmin = a+0.5*del; break;
case full_bins: del = (b-a)/(L-1); xmin = a; break;
case without_last: del = (b-a)/L; xmin = a; break;
}
xmax = xmin + del*(L-1);
}
domain_t const & domain() const { return _dom;}
size_t size() const { return L; }
double delta() const { return del; }
double x_max() const { return xmax; }
double x_min() const { return xmin; }
mesh_kind kind() const { return meshk; }
/// Conversions point <-> index <-> linear_index
domain_pt_t index_to_point (index_t ind) const {return embed(xmin + ind * del, mpl::bool_<boost::is_base_of<std::complex<double>, domain_pt_t>::value >()) ;}
private : // multiply by I is the type is a complex ....
domain_pt_t embed( double x, mpl::bool_<false> ) const { return x;}
domain_pt_t embed( double x, mpl::bool_<true> ) const { return std::complex<double>(0,x);}
public :
size_t index_to_linear(index_t ind) const {return ind;}
/// The wrapper for the mesh point
class mesh_point_t : tag::mesh_point, public arith_ops_by_cast<mesh_point_t, domain_pt_t > {
linear_mesh const * m;
index_t _index;
public:
mesh_point_t( linear_mesh const & mesh, index_t const & index_): m(&mesh), _index(index_) {}
void advance() { ++_index;}
typedef domain_pt_t cast_t;
operator cast_t () const { return m->index_to_point(_index);}
size_t linear_index() const { return _index;}
size_t index() const { return _index;}
bool at_end() const { return (_index == m->size());}
void reset() {_index =0;}
};
/// Accessing a point of the mesh
mesh_point_t operator[](index_t i) const { return mesh_point_t (*this,i);}
// ADDED for krylov : to be CLEANED AND CHANGED
// Find the index of the mesh point which is nearest to x
index_t nearest_index(domain_pt_t x) const {
double x_real = real_or_imag(x, std::is_base_of<std::complex<double>, domain_pt_t>());
using boost::math::round; using std::min; using std::max;
switch(meshk) {
case half_bins:
case full_bins: return min(max(round((x_real-xmin)/del),.0),static_cast<double>(L-1));
case without_last: return min(max(round((x_real-xmin)/del),.0),static_cast<double>(L-2));
}
}
private:
static double real_or_imag(domain_pt_t x, std::false_type) {return x; }
static double real_or_imag(domain_pt_t x, std::true_type) {return imag(x); }
public:
/// Iterating on all the points...
typedef mesh_pt_generator<linear_mesh> const_iterator;
const_iterator begin() const { return const_iterator (this);}
const_iterator end() const { return const_iterator (this, true);}
const_iterator cbegin() const { return const_iterator (this);}
const_iterator cend() const { return const_iterator (this, true);}
/// Mesh comparison
bool operator == (linear_mesh const & M) const { return ((_dom == M._dom) && (size() ==M.size()) && (std::abs(xmin - M.xmin)<1.e-15) && (std::abs(xmax - M.xmax)<1.e-15));}
bool operator != (linear_mesh const & M) const { return !(operator==(M));}
/// Write into HDF5
friend void h5_write (h5::group fg, std::string subgroup_name, linear_mesh const & m) {
h5::group gr = fg.create_group(subgroup_name);
int k;
switch(m.meshk) {
case half_bins: k=0; break;
case full_bins: k=1; break;
case without_last: k=2; break;
}
h5_write(gr,"domain",m.domain());
h5_write(gr,"min",m.a_pt);
h5_write(gr,"max",m.b_pt);
h5_write(gr,"size",m.size());
h5_write(gr,"kind",k);
}
/// Read from HDF5
friend void h5_read (h5::group fg, std::string subgroup_name, linear_mesh & m){
h5::group gr = fg.open_group(subgroup_name);
typename linear_mesh::domain_t dom;
double a,b;
size_t L;
int k;
mesh_kind mk;
h5_read(gr,"domain",dom);
h5_read(gr,"min",a);
h5_read(gr,"max",b);
h5_read(gr,"size",L);
h5_read(gr,"kind",k);
switch(k) {
case 0: mk = half_bins; break;
case 1: mk = full_bins; break;
case 2: mk = without_last; break;
}
m = linear_mesh(std::move(dom), a, b, L, mk);
}
// BOOST Serialization
friend class boost::serialization::access;
template<class Archive>
void serialize(Archive & ar, const unsigned int version) {
ar & boost::serialization::make_nvp("domain",_dom);
ar & boost::serialization::make_nvp("a_pt",a_pt);
ar & boost::serialization::make_nvp("b_pt",b_pt);
ar & boost::serialization::make_nvp("xmin",xmin);
ar & boost::serialization::make_nvp("xmax",xmax);
ar & boost::serialization::make_nvp("del",del);
ar & boost::serialization::make_nvp("size",L);
ar & boost::serialization::make_nvp("kind",meshk);
}
private:
domain_t _dom;
size_t L;
double a_pt, b_pt;
double xmin, xmax;
double del;
mesh_kind meshk;
};
// UNUSED
/// Simple approximation of a point of the domain by a mesh point. No check
template<typename D>
size_t get_closest_mesh_pt_index ( linear_mesh<D> const & mesh, typename D::point_t const & x) {
double a = (x - mesh.x_min())/mesh.delta();
return std::floor(a);
}
/// Approximation of a point of the domain by a mesh point
template<typename D>
std::tuple<bool, size_t, double> windowing ( linear_mesh<D> const & mesh, typename D::point_t const & x) {
double a = (x - mesh.x_min())/mesh.delta();
long i = std::floor(a);
bool in = (! ((i<0) || (i>long(mesh.size())-1)));
double w = a-i;
// std::cerr << " window "<< i << " "<< in << " "<< w<< std::endl ;
return std::make_tuple(in, (in ? size_t(i) : 0),w);
}
}}
#endif