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dft_tools/triqs/lattice/bravais_lattice_and_brillouin_zone.cpp
Olivier Parcollet fc2a620eae arrays: new ref counting and weak views
- improve the mem_block and shared_block.
- the reference counting is now done in the mem_block and shared_block, removing the need of shared_ptr.

- speed tests shows that shared_ptr is very slow (due to thread safety?)
the new version is much better, though not perfect.

- Hence introducing weak views.

- also :
-- clean the guard mechanism for python (to allow returning from python without any python ref left).
-- clean code, add documentation for mem_block
-- remove nan init, which was not working, and corresponding test
-- serialisation of view still unchanged (need to forbid serialization of view ??).

- tests ok, incl. valgrind tests.
2013-07-23 08:13:44 +02:00

97 lines
4.1 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2011 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/>.
*
******************************************************************************/
#include "bravais_lattice_and_brillouin_zone.hpp"
#include <triqs/arrays/blas_lapack/dot.hpp>
#include <triqs/arrays/linalg/inverse.hpp>
#include <triqs/arrays/linalg/cross_product.hpp>
namespace triqs { namespace lattice_tools {
using namespace tqa;
using namespace std;
//using triqs::arrays::blas::dot;
const double almost_zero(1E-10);
bravais_lattice::bravais_lattice( units_type const & units__) : units_(3,3), dim_(units__.len(0)) {
units_(range(0,dim_),range()) = units__();
units_(range(dim_,3),range()) = 0;
// First complete the basis. Add some tests for safety
tqa::vector<double> ux(3),uy(3),uz(3);
assert(dim_==2);
switch (dim_) {
case 1:
ux = units_(0,range());
uz() = 0; uz(1) = 1 ;
uz = uz - dot(uz,ux)* ux;
// no luck, ux was parallel to z, another one must work
if (sqrt(dot(uz,uz))<almost_zero) {
uz() = 0; uz(2) = 1; // 0,0,1;
uz = uz - dot(uz,ux)* ux;
}
uz /= sqrt(dot(uz,uz));
uy = cross_product(uz,ux);
uy = uy/sqrt(dot(uy,uy)); // uy can not be 0
units_(1,range()) = uz;
units_(2,range()) = uy;
break;
case 2:
uy() = 0; uy(2) = 1 ;
uy = cross_product(units_(0,range()),units_(1,range()));
double delta = sqrt(dot(uy,uy));
if (abs(delta)<almost_zero) TRIQS_RUNTIME_ERROR<<"Tiling : the 2 vectors of unit are not independent";
units_(2,range()) = uy /delta;
}
//cerr<<" Units = "<< units_<<endl;
}
//------------------------------------------------------------------------------------
brillouin_zone::brillouin_zone( bravais_lattice const & bl_) : lattice_(bl_), K_reciprocal(3,3) {
bravais_lattice::units_type Units(lattice().units());
std::cout << Units << std::endl;
double delta = dot(Units(0,range()), cross_product(Units(1,range()),Units(2,range())));
std::cout << dot(Units(0,range()), cross_product(Units(1,range()),Units(2,range())))<<std::endl;
std::cout << cross_product(Units(1,range()),Units(2,range()))<<std::endl;
if (abs(delta)<almost_zero) TRIQS_RUNTIME_ERROR<<"Tiling : the 3 vectors of Units are not independant";
K_reciprocal(0,range()) = cross_product(Units(1,range()),Units(2,range())) / delta;
K_reciprocal(1,range()) = cross_product(Units(2,range()),Units(0,range())) / delta;
K_reciprocal(2,range()) = cross_product(Units(0,range()),Units(1,range())) / delta;
//for (size_t i =0; i< lattice().dim();i++) std::cerr << " K_reciprocal(" << i << ")/(2pi) = " << K_reciprocal(i,range())<< std::endl;
const double pi = acos(-1.0);
K_reciprocal = K_reciprocal*2*pi;
K_reciprocal_inv = inverse(K_reciprocal);
}
K_view_type brillouin_zone::lattice_to_real_coordinates (K_view_type const & k) const {
if (k.size()!=lattice().dim()) TRIQS_RUNTIME_ERROR<<"latt_to_real_k : dimension of k must be "<<lattice().dim();
K_type res(3); res()=0; int dim = lattice().dim();
for (int i =0; i< dim;i++) res += k (i) * K_reciprocal(i,range());
return(res);
}
K_view_type brillouin_zone::real_to_lattice_coordinates (K_view_type const & k) const {
if (k.size()!=lattice().dim()) TRIQS_RUNTIME_ERROR<<"latt_to_real_k : dimension of k must be "<<lattice().dim();
K_type res(3);res()=0; int dim = lattice().dim();
for (int i =0; i< dim;i++) res += k (i) * K_reciprocal_inv(i,range());
return(res);
}
}}//namespaces