cgal/QP_solver/include/CGAL/QP_solver/QP_basis_inverse.h

1136 lines
36 KiB
C++

// Copyright (c) 1997-2001 ETH Zurich (Switzerland).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
//
//
// Author(s) : Sven Schoenherr <sven@inf.fu-berlin.de>
// Bernd Gaertner <gaertner@inf.ethz.ch>
// Franz Wessendorp <fransw@inf.ethz.ch>
// Kaspar Fischer <fischerk@inf.ethz.ch>
#ifndef CGAL_QP_SOLVER_QP_BASIS_INVERSE_H
#define CGAL_QP_SOLVER_QP_BASIS_INVERSE_H
#include <CGAL/QP_solver/basic.h>
#include <CGAL/IO/Verbose_ostream.h>
#include <vector>
CGAL_BEGIN_NAMESPACE
// =================
// class declaration
// =================
template < class ET_, class Is_LP_ >
class QP_basis_inverse;
// ===============
// class interface
// ===============
template < class ET_, class Is_LP_ >
class QP_basis_inverse {
public:
// self
typedef ET_ ET;
typedef Is_LP_ Is_LP;
typedef QP_basis_inverse<ET,Is_LP>
Self;
private:
// private types
typedef std::vector<ET> Row;
typedef std::vector<Row> Matrix;
public:
/*
* Note: Some member functions below are suffixed with '_'.
* They are member templates and their declaration is "hidden",
* because they are also implemented in the class interface.
* This is a workaround for M$-VC++, which otherwise fails to
* instantiate them correctly.
*/
// creation and initialization
// ---------------------------
QP_basis_inverse( CGAL::Verbose_ostream& verbose_ostream);
// set-up
void set( int n, int m, int nr_equalities);
// init
template < class InputIterator > // phase I
void init_( unsigned int art_size, InputIterator art_first);
/*
template < class InputIterator > // phase II
void init_( ...);
*/
// transition to phase II
template < class InputIterator > // QP case
void transition_( InputIterator twice_D_it);
void transition( ); // LP case
// access
// ------
const ET& denominator( ) const { return d; }
const ET& entry( unsigned int row, unsigned int column) const
{ return entry( row, column, Is_LP()); }
// multiplication functions
// ------------------------
// matrix-vector multiplication ( y = M v )
template < class ForwardIterator, class OutputIterator > inline
void multiply( ForwardIterator v_l_it, ForwardIterator v_x_it,
OutputIterator y_l_it, OutputIterator y_x_it) const
{ multiply( v_l_it, v_x_it, y_l_it, y_x_it, Is_LP(), Tag_true()); }
// special matrix-vector multiplication functions for LPs
template < class ForwardIterator, class OutputIterator > inline
void multiply_l( ForwardIterator v_x_it, OutputIterator y_l_it) const
{ CGAL_qpe_precondition( is_LP || is_phaseI);
multiply__l( v_x_it, y_l_it); }
template < class ForwardIterator, class OutputIterator > inline
void multiply_x( ForwardIterator v_l_it, OutputIterator y_x_it) const
{ CGAL_qpe_precondition( is_LP || is_phaseI);
multiply__x( v_l_it, y_x_it); }
// vector-matrix multiplication ( x^T = u^T M )
template < class ForwardIterator, class OutputIterator > inline
void multiply_transposed( ForwardIterator u_l_it, ForwardIterator u_x_it,
OutputIterator x_l_it, OutputIterator x_x_it)
const
{ multiply( u_l_it, u_x_it, x_l_it, x_x_it); } // M_B^{-1} is symmetric
// special vector-matrix multiplication functions for LPs
template < class ForwardIterator, class OutputIterator > inline
void multiply_transposed_l( ForwardIterator u_x_it,
OutputIterator x_l_it) const
{ multiply_l( u_x_it, x_l_it); } // Note: M_B^{-1} is symmetric
template < class ForwardIterator, class OutputIterator > inline
void multiply_transposed_x( ForwardIterator u_l_it,
OutputIterator x_x_it) const
{ multiply_x( u_l_it, x_x_it); } // Note: M_B^{-1} is symmetric
// vector-vector multiplication ( y = u^T v )
template < class InputIterator1, class InputIterator2 > inline
typename std::iterator_traits<InputIterator1>::value_type
inner_product( InputIterator1 u_l_it, InputIterator1 u_x_it,
InputIterator2 v_l_it, InputIterator2 v_x_it) const
{ return inner_product_l( u_l_it, v_l_it)
+ inner_product_x( u_x_it, v_x_it); }
template < class InputIterator1, class InputIterator2 > inline
typename std::iterator_traits<InputIterator1>::value_type
inner_product_l( InputIterator1 u_l_it, InputIterator2 v_l_it) const
{ return inner_product( u_l_it, v_l_it, s); }
template < class InputIterator1, class InputIterator2 > inline
typename std::iterator_traits<InputIterator1>::value_type
inner_product_x( InputIterator1 u_x_it, InputIterator2 v_x_it) const
{ return inner_product( u_x_it, v_x_it, b); }
// update functions
// ----------------
// entering of original variable (update type U1)
template < class ForwardIterator >
void enter_original_( ForwardIterator y_l_it,
ForwardIterator y_x_it, const ET& z);
// leaving of original variable (update type U2)
void leave_original( );
// entering of slack variable (update type U3)
void enter_slack( );
// leaving of slack variable (update type U4)
template < class ForwardIterator >
void leave_slack_( ForwardIterator u_x_it);
// replacing of original by original variable (update type U5)
template < class ForwardIterator >
void enter_original_leave_original_( ForwardIterator y, unsigned int k);
// replacing of slack by slack variable (update type U6)
template < class ForwardIterator >
void enter_slack_leave_slack_( ForwardIterator u, unsigned int k);
// replacing of slack by original variable (update type U7)
template < class ForwardIterator1, class ForwardIterator2 >
void enter_original_leave_slack_( ForwardIterator1 y, ForwardIterator2 u);
// replacing of original by slack variable (update type U8)
void enter_slack_leave_original( );
// replacing of original by original variable with precondition in QP-case
// for phaseII (update type UZ_1)
template < class ForwardIterator >
void z_replace_original_by_original(ForwardIterator y_l_it,
ForwardIterator y_x_it,
const ET& s_delta, const ET& s_nu,
unsigned int k_i);
// replacing of original by slack variable with precondition in QP-case
// for phaseII (update type UZ_2)
void z_replace_original_by_slack( );
// replacing of slack by original variable with precondition in QP-case
// for phaseII (update type UZ_3)
template < class ForwardIterator >
void z_replace_slack_by_original(ForwardIterator y_l_it,
ForwardIterator y_x_it,
ForwardIterator u_x_it, const ET& hat_kappa,
const ET& hat_nu);
// replacing of slack by slack variable with precondition in QP-case
// for phaseII (update type UZ_4)
template < class ForwardIterator >
void z_replace_slack_by_slack(ForwardIterator u_x_it, unsigned int k_j);
// copying of reduced basis inverse row in (upper) C-half
template < class OutIt >
void copy_row_in_C(OutIt y_l_it, OutIt y_x_it, unsigned int k);
// copying of reduced basis inverse row in (lower) B_O-half
template < class OutIt >
void copy_row_in_B_O(OutIt y_l_it, OutIt y_x_it, unsigned int k);
// swap functions
void swap_variable( unsigned int j) // ``to the end'' of R
{ CGAL_qpe_precondition( j < b);
swap_variable( j, Is_LP()); }
void swap_constraint( unsigned int i) // ``to the end'' of P
{ CGAL_qpe_precondition( i < s);
swap_constraint( i, Is_LP()); }
private:
// constants
const ET et0, et1, et2;
// data members
Matrix M; // basis inverse, stored row-wise
ET d; // denominator
unsigned int l; // minimum of `n' and `m'
unsigned int s; // size of `E \cup S_N'
unsigned int b; // size of `B_O'
bool is_phaseI; // flag indicating phase I
bool is_phaseII;// flag indicating phase II
const bool is_LP; // flag indicating a linear program
const bool is_QP; // flag indicating a quadratic program
CGAL::Verbose_ostream& vout; // used for diagnostic output
Row x_l, tmp_l; // used in the
Row x_x, tmp_x; // update functions
// private member functions
// ------------------------
// set-up
void set( Tag_false); // QP case
void set( Tag_true ); // LP case
// init
template < class InIt > // QP case
void init_( unsigned int art_size, InIt art_first, Tag_false);
template < class InIt > // LP case
void init_( unsigned int art_size, InIt art_first, Tag_true );
// access
const ET& entry( unsigned int row,
unsigned int column, Tag_false) const; // QP case
const ET& entry( unsigned int row,
unsigned int column, Tag_true ) const; // LP case
// matrix-vector multiplication
template < class ForIt, class OutIt, class Use1stArg > // QP case
void multiply_( ForIt v_l_it, ForIt v_x_it,
OutIt y_l_it, OutIt y_x_it, Tag_false, Use1stArg) const;
template < class ForIt, class OutIt, class DummyArg > // LP case
void multiply_( ForIt v_l_it, ForIt v_x_it,
OutIt y_l_it, OutIt y_x_it, Tag_true, DummyArg) const;
// special matrix-vector multiplication functions for LPs
template < class ForIt, class OutIt >
void multiply__l_( ForIt v_x_it, OutIt y_l_it) const;
template < class ForIt, class OutIt >
void multiply__x_( ForIt v_l_it, OutIt y_x_it) const;
// in-place update
template < class ForIt > // QP case
void update_inplace_QP_( ForIt y_l_it, ForIt y_x_it,
const ET& d_new, const ET& d_old);
template < class ForIt1, class ForIt2 > // LP case
void update_inplace_LP_( ForIt1 x_x_it, ForIt2 y_x_it,
const ET& d_new, const ET& d_old);
template < class ForIt > // QP case only
void z_update_inplace( ForIt psi1_l_it, ForIt psi1_x_it,
ForIt psi2_l_it, ForIt psi2_x_it,
const ET& omega0, const ET& omega1,
const ET& omega2, const ET& omega3);
void update_entry( ET& entry, const ET& d_new,
const ET& y, const ET& d_old) const;
// swap functions
void swap_variable ( unsigned int, Tag_true ); // LP case
void swap_variable ( unsigned int, Tag_false); // QP case
void swap_constraint( unsigned int, Tag_true ); // LP case
void swap_constraint( unsigned int, Tag_false); // QP case
// diagnostic output
void print( );
// ----------------------------------------------------------------------------
// ===============================
// class implementation (template)
// ===============================
public:
// creation and initialization
// ---------------------------
// init
template < class InputIterator >
void
init( unsigned int art_size, InputIterator art_first)
{
CGAL_qpe_precondition_msg( art_size <= l, \
"There are more equality constraints than original variables!");
init( art_size, art_first, Is_LP());
d = et1;
CGAL_qpe_postcondition( s == art_size);
CGAL_qpe_postcondition( b == art_size);
is_phaseI = true;
is_phaseII = false;
if ( x_x.size() < art_size) {
x_x.insert( x_x.end(), art_size-x_x.size(), et0);
}
if ( tmp_x.size() < art_size) {
tmp_x.insert( tmp_x.end(), art_size-tmp_x.size(), et0);
}
CGAL_qpe_debug {
if ( vout.verbose()) print();
}
}
// transition to phase II
template < class InputIterator > // QP case
void transition( InputIterator twice_D_it)
{
typename Matrix::iterator m_it1, m_it2, p_begin, r_begin;
typename Row ::iterator x_it;
unsigned int row, col;
// fill missing rows
for (row= 0; row< s; ++ row) {
CGAL_qpe_assertion(M[row].size()==0);
M[row].insert(M[row].end(), row+1, et0);
}
// compute new basis inverse [ upper-left part: -(Q^T * 2 D_B * Q) ]
// -----------------------------------------------------------------
// compute 'Q^T * 2 D_B' ( Q = A_B^-1 )
p_begin = M.begin();
r_begin = M.begin();
if (b > 0) r_begin += l+s-1; // initialize only if for loops
// are entered
for ( col = 0; col < b; ++col, ++twice_D_it) {
++p_begin;
// get column of D (D symmetric)
std::copy( *twice_D_it, *twice_D_it+b, x_l.begin());
// compute 'Q^T * 2 D_Bj'
multiply__l( x_l.begin(), x_x.begin());
// store resulting column in 'P' and 'R'
x_it = x_x.begin();
m_it2 = r_begin;
for ( row = l+col; row >= l; --row, --m_it2, ++x_it) {
(*m_it2)[ row] = *x_it;
}
m_it1 = p_begin;
for ( row = col+1; row < s; ++row, ++m_it1, ++x_it) {
(*m_it1)[ col] = *x_it;
}
}
// compute '(Q^T * 2 D_B) * Q' ( Q = A_B^-1 )
m_it1 = M.begin();
m_it2 = r_begin;
for ( row = 0; row < s; ++row, ++m_it1, --m_it2) {
// get row of '(Q^T * 2 D_B)' (stored in 'P' and 'R')
std::copy(m_it1->begin() ,m_it1->begin()+row, x_l.begin());
std::copy(m_it2->begin()+l,m_it2->begin()+(l+b-row),
x_l.begin()+row);
// compute '(Q^T * 2 D_B)_i * Q'
multiply__l( x_l.begin(), x_x.begin());
// negate and store result in 'P'
std::transform( x_x.begin(), x_x.begin()+row+1,
m_it1->begin(), std::negate<ET>());
// clean up in 'R'
std::fill_n( m_it2->begin()+l, b-row, et0);
}
// scale A_B^-1
m_it1 = M.begin()+l;
for ( row = 0; row < s; ++row, ++m_it1) {
std::transform( m_it1->begin(), m_it1->begin()+s, m_it1->begin(),
std::bind2nd( std::multiplies<ET>(), d));
}
// new denominator: |det(A_B)|^2
d *= d;
// update status
transition();
}
// update functions
// ----------------
// entering of original variable (update type U1)
template < class ForwardIterator >
void
enter_original( ForwardIterator y_l_it,
ForwardIterator y_x_it, const ET& z)
{
// assert QP case
Assert_compile_time_tag( Tag_false(), Is_LP());
// update matrix in-place
// ----------------------
// handle sign of new denominator
CGAL_qpe_precondition( z != et0);
bool z_neg = ( z < et0);
// update matrix
update_inplace_QP( y_l_it, y_x_it, z, ( z_neg ? -d : d));
// append new row and column ("after R")
// -------------------------------------
typename Row::iterator row_it;
ForwardIterator y_it;
unsigned int col, k = l+(++b);
// // allocate new row, if necessary
// // BG: replaced this by the ensure_physical_row construct below
// if ( k <= M.size()) {
// row_it = M[ k-1].begin();
// } else {
// row_it = M.insert( M.end(), Row( k, et0))->begin();
// x_x.push_back( et0);
// tmp_x.push_back( et0);
// }
ensure_physical_row(k-1);
row_it = M[ k-1].begin();
// store entries in new row
for ( col = 0, y_it = y_l_it;
col < s;
++col, ++row_it, ++y_it ) {
*row_it = ( z_neg ? *y_it : -( *y_it));
}
for ( col = l, row_it += l-s, y_it = y_x_it;
col < k-1;
++col, ++row_it, ++y_it ) {
*row_it = ( z_neg ? *y_it : -( *y_it));
}
*row_it = ( z_neg ? -d : d);
// store new denominator
// ---------------------
d = ( z_neg ? -z : z);
CGAL_qpe_postcondition( d > et0);
CGAL_qpe_debug {
if ( vout.verbose()) print();
}
}
// leaving of slack variable (update type U4)
template < class ForwardIterator >
void
leave_slack( ForwardIterator u_x_it)
{
// assert QP case
Assert_compile_time_tag( Tag_false(), Is_LP());
// update matrix in-place
// ----------------------
// compute new row/column of basis inverse
multiply( u_x_it, // dummy (not used)
u_x_it, x_l.begin(), x_x.begin(),
Tag_false(), // QP
Tag_false()); // ignore 1st argument
ET z = -inner_product_x( x_x.begin(), u_x_it);
bool z_neg = ( z < et0);
CGAL_qpe_precondition( z != et0);
// update matrix
update_inplace_QP( x_l.begin(), x_x.begin(), z, ( z_neg ? -d : d));
// insert new row and column ("after P")
// -------------------------------------
typename Row ::iterator row_it, x_it;
typename Matrix::iterator col_it;
unsigned int col, k = l+b;
// store entries in new row
if (M[s].size()==0) {
// row has to be filled first
M[s].insert(M[s].end(), s+1, et0);
}
for ( col = 0, row_it = M[ s].begin(), x_it = x_l.begin();
col < s;
++col, ++row_it, ++x_it ) {
*row_it = ( z_neg ? *x_it : -( *x_it));
}
*row_it = ( z_neg ? -d : d);
for ( col = l, col_it = M.begin()+l, x_it = x_x.begin();
col < k;
++col, ++col_it, ++x_it ) {
(*col_it)[ s] = ( z_neg ? *x_it : -( *x_it));
}
++s;
// store new denominator
// ---------------------
d = ( z_neg ? -z : z);
CGAL_qpe_postcondition( d > et0);
CGAL_qpe_debug {
if ( vout.verbose()) print();
}
}
// replacing of original variable (update type U5) [ replace column ]
template < class RandomAccessIterator >
void
enter_original_leave_original( RandomAccessIterator y_x_it, unsigned int k)
{
// assert LP case or phase I
CGAL_qpe_precondition( is_LP || is_phaseI);
CGAL_qpe_precondition( k < b);
// update matrix in place
// ----------------------
typename Matrix::iterator matrix_it;
typename Row ::iterator row_it, row_k_it, row_k;
// handle sign of new denominator
ET z = y_x_it[ k];
bool z_neg = ( z < et0);
if ( z_neg) d = -d;
// QP (in phase I)?
matrix_it = M.begin();
if ( is_QP) matrix_it += l;
row_k = ( matrix_it+k)->begin();
// rows: 0..s-1 without k
unsigned int row, col;
ET minus_y;
for ( row = 0;
row < s;
++row, ++matrix_it, ++y_x_it) {
if ( row != k) {
// columns: 0..b-1
minus_y = -( *y_x_it);
for ( col = 0, row_it = matrix_it->begin(), row_k_it = row_k;
col < b;
++col, ++row_it, ++row_k_it ){
// update in place
update_entry( *row_it, z, minus_y * *row_k_it, d);
}
}
}
// rows: k (flip signs, if necessary)
if ( z_neg) {
for ( col = 0, row_it = row_k;
col < b;
++col, ++row_it ) {
*row_it = -( *row_it);
}
}
// store new denominator
// ---------------------
d = ( z_neg ? -z : z);
CGAL_qpe_postcondition( d > et0);
// diagnostic output
CGAL_qpe_debug {
if ( vout.verbose()) print();
}
}
// replacing of slack variable (update type U6) [ replace row ]
template < class ForwardIterator >
void
enter_slack_leave_slack( ForwardIterator u_x_it, unsigned int k)
{
// assert LP case or phase I
CGAL_qpe_precondition( is_LP || is_phaseI);
CGAL_qpe_precondition( k < s);
// compute new row of basis inverse
multiply__l( u_x_it, x_x.begin());
// update matrix in place
// ----------------------
typename Matrix::iterator matrix_it;
typename Row ::iterator row_it, x_it;
// handle sign of new denominator
ET z = x_x[ k];
bool z_neg = ( z < et0);
if ( z_neg) d = -d;
// QP (in phase I)?
matrix_it = M.begin();
if ( is_QP) matrix_it += l;
// rows: 0..s-1
unsigned int row, col;
ET minus_m_row;
for ( row = 0;
row < s;
++row, ++matrix_it) {
// columns: 0..b-1
minus_m_row = -( *matrix_it)[ k];
for ( col = 0, row_it = matrix_it->begin(), x_it = x_x.begin();
col < b;
++col, ++row_it, ++x_it ){
if ( col != k) { // all columns but k
// update in place
update_entry( *row_it, z, minus_m_row * *x_it, d);
} else { // column k
// flip sign, if necessary
if ( z_neg) *row_it = -( *row_it);
}
}
}
// store new denominator
// ---------------------
d = ( z_neg ? -z : z);
CGAL_qpe_postcondition( d > et0);
// diagnostic output
CGAL_qpe_debug {
if ( vout.verbose()) print();
}
}
// replacing of slack by original variable (update type U7) [ grow ]
template < class ForwardIterator1, class ForwardIterator2 >
void enter_original_leave_slack( ForwardIterator1 y_x_it,
ForwardIterator2 u_x_it)
{
// assert LP case or phase I
CGAL_qpe_precondition( is_LP || is_phaseI);
// update matrix in-place
// ----------------------
// compute new row of basis inverse
multiply__l( u_x_it, x_x.begin());
ET z = d*u_x_it[ b] - inner_product_x( y_x_it, u_x_it);
bool z_neg = ( z < et0);
CGAL_qpe_precondition( z != et0);
// update matrix
update_inplace_LP( x_x.begin(), y_x_it, z, ( z_neg ? -d : d));
// append new row and column
// -------------------------
typename Matrix::iterator matrix_it;
typename Row ::iterator row_it, x_it;
unsigned int row, col;
// QP (in phase I)?
if ( is_QP) {
ensure_physical_row(l+b);
row_it = M[l+b].begin();
matrix_it = M.begin() + l;
} else {
row_it = M[s].begin();
matrix_it = M.begin();
}
// store 'x_x' in new row
x_it = x_x.begin();
for ( col = 0; col < b; ++col, ++row_it, ++x_it) {
*row_it = ( z_neg ? *x_it : -( *x_it));
}
*row_it = ( z_neg ? -d : d);
// store 'y_x' in new col
for ( row = 0; row < s; ++row, ++matrix_it, ++y_x_it) {
(*matrix_it)[b] = ( z_neg ? *y_x_it : -( *y_x_it));
}
++s; ++b;
// store new denominator
// ---------------------
d = ( z_neg ? -z : z);
CGAL_qpe_postcondition( d > et0);
CGAL_qpe_debug {
if ( vout.verbose()) print();
}
}
// due to basis_matrix_stays_regular fix, needs reconsideration
//private:
// private member functions
// ------------------------
// init (QP case)
template < class InIt > inline
void
init( unsigned int art_size, InIt art_first, Tag_false)
{
// only Q is used to store A_B^-1 in phase I
for ( s = l, b = 0; b < art_size; ++s, ++b, ++art_first) {
ensure_physical_row(s);
M[ s][ b] = ( art_first->second ? -et1 : et1);
}
s = art_size;
}
// init (LP case)
template < class InIt > inline
void
init( unsigned int art_size, InIt art_first, Tag_true)
{
for ( s = 0; s < art_size; ++s, ++art_first) {
std::fill_n( M[ s].begin(), art_size, et0);
M[ s][ s] = ( art_first->second ? -et1 : et1);
}
b = art_size;
}
// append row in Q if no allocated row available
void ensure_physical_row (unsigned int row) {
unsigned int rows = M.size();
CGAL_qpe_precondition(rows >= row);
if (rows == row) {
M.push_back(Row(row+1, et0));
// do we have to grow x_x?
CGAL_qpe_precondition(x_x.size() >= row-l);
if (x_x.size() == row-l)
x_x.push_back(et0);
// do we have to grow tmp_x?
CGAL_qpe_precondition(tmp_x.size() >= row-l);
if (tmp_x.size() == row-l)
tmp_x.push_back(et0);
CGAL_qpe_postcondition(M[row].size()==row+1);
CGAL_qpe_debug {
if ( vout.verbose()) {
vout << "physical row " << (row) << " appended in Q\n";
}
}
}
}
// matrix-vector multiplication (QP case)
template < class ForIt, class OutIt, class Use1stArg >
void
multiply( ForIt v_l_it, ForIt v_x_it,
OutIt y_l_it, OutIt y_x_it, Tag_false,
Use1stArg use_1st_arg) const
{
// use 'LP' functions in phase I
if ( is_phaseI) {
multiply__l( v_x_it, y_l_it);
multiply__x( v_l_it, y_x_it);
return;
}
// phase II
typename Matrix::const_iterator matrix_it;
typename Row ::const_iterator row_it; // left of diagonal
typename Matrix::const_iterator column_it; // right of diagonal
ForIt v_it;
unsigned int row, count, k = l+b;
ET sum;
// compute P v_l + Q^T v_x
for ( row = 0, matrix_it = M.begin();
row < s;
++row, ++y_l_it) {
sum = et0;
// P v_l
if ( check_tag( use_1st_arg)) {
// P: left of diagonal (including)
for ( row_it = matrix_it->begin(), v_it = v_l_it;
row_it != matrix_it->end();
++row_it, ++v_it) {
sum += *row_it * *v_it;
}
// P: right of diagonal (excluding)
for ( count = row+1, column_it = ++matrix_it;
count < s;
++count, ++column_it, ++v_it) {
sum += (*column_it)[ row] * *v_it;
}
}
// Q^T:
for ( count = 0, column_it = M.begin()+l, v_it = v_x_it;
count < b;
++count, ++column_it, ++v_it) {
sum += (*column_it)[ row] * *v_it;
}
// store result
*y_l_it = sum;
}
// compute Q v_l + R v_x
for ( row = l, matrix_it = M.begin()+l;
row < k;
++row, ++y_x_it) {
sum = et0;
// Q v_l
if ( check_tag( use_1st_arg)) {
// Q:
for ( count = 0, row_it = matrix_it->begin(), v_it = v_l_it;
count < s;
++count, ++row_it, ++v_it) {
sum += *row_it * *v_it;
}
}
// R: left of diagonal (including)
for ( row_it = matrix_it->begin()+l, v_it = v_x_it;
row_it != matrix_it->end();
++row_it, ++v_it) {
sum += *row_it * *v_it;
}
// R: right of diagonal (excluding)
for ( count = row+1, column_it = ++matrix_it;
count < k;
++count, ++column_it, ++v_it) {
sum += (*column_it)[ row] * *v_it;
}
// store result
*y_x_it = sum;
}
}
// matrix-vector multiplication (LP case)
template < class ForIt, class OutIt, class Dummy > inline
void
multiply( ForIt v_l_it, ForIt v_x_it,
OutIt y_l_it, OutIt y_x_it, Tag_true, Dummy) const
{
multiply__l( v_x_it, y_l_it);
multiply__x( v_l_it, y_x_it);
}
// special matrix-vector multiplication functions for LPs
template < class ForIt, class OutIt > inline
void
multiply__l( ForIt v_x_it, OutIt y_l_it) const
{
typename Matrix::const_iterator matrix_it = M.begin();
typename Matrix::const_iterator column_it;
ForIt v_it;
unsigned int row, count;
ET sum;
// QP?
if ( is_QP) matrix_it += l;
// compute Q^T v_x
for ( row = 0; row < s; ++row, ++y_l_it) {
sum = et0;
for ( count = 0, column_it = matrix_it, v_it = v_x_it;
count < b;
++count, ++column_it, ++v_it) {
sum += (*column_it)[ row] * *v_it;
}
*y_l_it = sum;
}
}
template < class ForIt, class OutIt > inline
void
multiply__x( ForIt v_l_it, OutIt y_x_it) const
{
typename Matrix::const_iterator matrix_it = M.begin();
unsigned int row;
// QP?
if ( is_QP) matrix_it += l;
// compute Q v_l
for ( row = 0;
row < b;
++row, ++matrix_it, ++y_x_it) {
*y_x_it = inner_product( matrix_it->begin(), v_l_it, s);
}
}
// vector-vector multiplication
template < class InIt1, class InIt2 > inline
typename std::iterator_traits<InIt1>::value_type
inner_product( InIt1 u_it, InIt2 v_it, unsigned int n) const
{
typedef typename std::iterator_traits<InIt1>::value_type NT;
// compute u^T v
NT sum = NT( 0);
for ( unsigned int count = 0; count < n; ++count, ++u_it, ++v_it) {
sum += NT(*u_it) * NT(*v_it);
}
return sum;
}
// in-place update
template < class ForIt > // QP case
void update_inplace_QP( ForIt y_l_it, ForIt y_x_it,
const ET& d_new, const ET& d_old)
{
typename Matrix:: iterator matrix_it;
typename Row :: iterator row_it;
typename Row ::const_iterator y_it1, y_it2;
unsigned int row, col, k = l+b;
// rows: 0..s-1 ( P )
for ( row = 0, y_it1 = y_l_it, matrix_it = M.begin();
row < s;
++row, ++y_it1, ++matrix_it ) {
// columns: 0..row ( P )
for ( row_it = matrix_it->begin(), y_it2 = y_l_it;
row_it != matrix_it->end();
++row_it, ++y_it2 ) {
update_entry( *row_it, d_new, *y_it1 * *y_it2, d_old);
}
}
// rows: l..k-1 ( Q R )
for ( row = l, y_it1 = y_x_it, matrix_it += l-s;
row < k;
++row, ++y_it1, ++matrix_it ) {
// columns: 0..s-1 ( Q )
for ( col = 0, row_it = matrix_it->begin(), y_it2 = y_l_it;
col < s;
++col, ++row_it, ++y_it2 ){
update_entry( *row_it, d_new, *y_it1 * *y_it2, d_old);
}
// columns: l..k-1 ( R )
for ( row_it += l-s, y_it2 = y_x_it;
row_it != matrix_it->end();
++row_it, ++y_it2 ){
update_entry( *row_it, d_new, *y_it1 * *y_it2, d_old);
}
}
}
template < class ForIt1, class ForIt2 > // LP case
void update_inplace_LP( ForIt1 x_x_it, ForIt2 y_x_it,
const ET& d_new, const ET& d_old)
{
typename Matrix:: iterator matrix_it;
typename Row :: iterator row_it;
ForIt1 x_it;
unsigned int row, col;
ET y;
// QP (in phase I)?
matrix_it = M.begin();
if ( is_QP) matrix_it += l;
// rows: 0..s-1 ( Q )
for ( row = 0;
row < s;
++row, ++y_x_it, ++matrix_it) {
// columns: 0..b-1 ( Q )
y = *y_x_it;
for ( col = 0, row_it = matrix_it->begin(), x_it = x_x_it;
col < b;
++col, ++row_it, ++x_it ){
update_entry( *row_it, d_new, y * *x_it, d_old);
}
}
}
template < class RandomAccessIterator >
typename std::iterator_traits<RandomAccessIterator>::value_type
inv_M_B_row_dot_col( int row, RandomAccessIterator u_l_it) const
{
typename Row::const_iterator row_it;
if ( is_QP) {
row_it = M[l + row].begin();
} else {
row_it = M[row].begin();
}
return inner_product(row_it, u_l_it, b);
}
};
// ----------------------------------------------------------------------------
// =============================
// class implementation (inline)
// =============================
// creation
template < class ET_, class Is_LP_ > inline
QP_basis_inverse<ET_,Is_LP_>::
QP_basis_inverse( CGAL::Verbose_ostream& verbose_ostream)
: et0( 0), et1( 1), et2( 2),
is_LP( check_tag( Is_LP())), is_QP( ! is_LP),
vout( verbose_ostream)
{ }
// transition (LP case)
template < class ET_, class Is_LP_ > inline
void QP_basis_inverse<ET_,Is_LP_>::
transition( )
{
is_phaseI = false;
is_phaseII = true;
CGAL_qpe_debug {
if ( vout.verbose()) print();
}
}
// set-up (QP case)
template < class ET_, class Is_LP_ > inline
void QP_basis_inverse<ET_,Is_LP_>::
set( Tag_false)
{
M.reserve( l);
// only allocate empty rows
for ( unsigned int i = 0; i < l; ++i )
M.push_back(Row(0, et0));
}
// set-up (LP case)
template < class ET_, class Is_LP_ > inline
void QP_basis_inverse<ET_,Is_LP_>::
set( Tag_true)
{
M.reserve( l);
for ( unsigned int i = 0; i < l; ++i) M.push_back( Row( l, et0));
}
// access (QP case)
template < class ET_, class Is_LP_ > inline
const ET_& QP_basis_inverse<ET_,Is_LP_>::
entry( unsigned int r, unsigned int c, Tag_false) const
{
CGAL_qpe_precondition( ( r < s) || ( ( r >= l) && ( r < l+b)));
CGAL_qpe_precondition( ( c < s) || ( ( c >= l) && ( c < l+b)));
return ( c < r ? M[ r][ c] : M[ c][ r]);
}
// access (LP case)
template < class ET_, class Is_LP_ > inline
const ET_& QP_basis_inverse<ET_,Is_LP_>::
entry( unsigned int r, unsigned int c, Tag_true) const
{
CGAL_qpe_precondition( r < s);
CGAL_qpe_precondition( c < b);
return M[ r][ c];
}
// in-place update
template < class ET_, class Is_LP_ > inline
void QP_basis_inverse<ET_,Is_LP_>::
update_entry( ET& entry, const ET& d_new, const ET& y, const ET& d_old) const
{
entry *= d_new;
entry += y;
entry = CGAL::integral_division(entry, d_old);
}
CGAL_END_NAMESPACE
#include <CGAL/QP_solver/QP_basis_inverse_impl.h>
#endif // CGAL_QP_SOLVER_QP_BASIS_INVERSE_H
// ===== EOF ==================================================================