Definition

A model of NonnegativeQuadraticProgram describes a convex quadratic program of the form.

\begin{eqnarray*} \mbox{(QP)}& \mbox{minimize} & \qpx^{T}D\qpx+\qpc^{T}\qpx+c_0 \\ &\mbox{subject to} & A\qpx\qprel \qpb, \\ & & \qpx \geq 0 \end{eqnarray*}

in \( n\) real variables \( \qpx=(x_0,\ldots,x_{n-1})\). Here,

\( A\) is an \( m\times n\) matrix (the constraint matrix),
\( \qpb\) is an \( m\)-dimensional vector (the right-hand side),
\( \qprel\) is an \( m\)-dimensional vector of relations from \( \{\leq, =, \geq\}\),
\( D\) is a symmetric positive-semidefinite \( n\times n\) matrix (the quadratic objective function),
\( \qpc\) is an \( n\)-dimensional vector (the linear objective function), and
\( c_0\) is a constant.

The description is given by appropriate random-access iterators over the program data, see below. The program therefore comes in dense representation which includes zero entries.

Has models
: CGAL::Quadratic_program<NT>
: CGAL::Quadratic_program_from_mps<NT>
: CGAL::Nonnegative_quadratic_program_from_iterators<A_it, B_it, R_it, FL_it, L_it, FU_it, U_it, D_it, C_it>

The value types of all iterator types (nested iterator types, respectively, for A_iterator and D_iterator) must be convertible to some common IntegralDomain ET.

See also: QuadraticProgram; LinearProgram; NonnegativeLinearProgram

Types
typedef unspecified_type	A_iterator
	A random access iterator type to go columnwise over the constraint matrix \( A\).

typedef unspecified_type	B_iterator
	A random access iterator type to go over the entries of the right-hand side \( \qpb\).

typedef unspecified_type	R_iterator
	A random access iterator type to go over the relations \( \qprel\).

typedef unspecified_type	D_iterator
	A random access iterator type to go rowwise over the matrix \( 2D\).

typedef unspecified_type	C_iterator
	A random access iterator type to go over the entries of the linear objective function vector \( c\).

Operations
int	get_n () const
	returns the number \( n\) of variables (number of columns of \( A\)) in `qp`.

int	get_m () const
	returns the number \( m\) of constraints (number of rows of \( A\)) in `qp`.

A_iterator	get_a () const
	returns an iterator over the columns of \( A\).

B_iterator	get_b () const
	returns an iterator over the entries of \( \qpb\).

R_iterator	get_r () const
	returns an iterator over the entries of \( \qprel\).

D_iterator	get_d () const
	returns an iterator over the rows of \( 2D\).

C_iterator	get_c () const
	returns an iterator over the entries of \( \qpc\).

std::iterator_traits< C_iterator >::value_type	get_c0 () const
	returns the constant term \( c_0\) of the objective function.

Member Typedef Documentation

◆ A_iterator

typedef unspecified_type NonnegativeQuadraticProgram::A_iterator

A random access iterator type to go columnwise over the constraint matrix \( A\).

The value type is a random access iterator type for an individual column that goes over the entries in that column.

◆ D_iterator

typedef unspecified_type NonnegativeQuadraticProgram::D_iterator

A random access iterator type to go rowwise over the matrix \( 2D\).

The value type is a random access iterator type for an individual row that goes over the entries in that row, up to (and including) the entry on the main diagonal.

◆ R_iterator

typedef unspecified_type NonnegativeQuadraticProgram::R_iterator

A random access iterator type to go over the relations \( \qprel\).

The value type of R_iterator is CGAL::Comparison_result.

Member Function Documentation

◆ get_a()

A_iterator NonnegativeQuadraticProgram::get_a ( ) const

returns an iterator over the columns of \( A\).

The corresponding past-the-end iterator is get_a()+get_n(). For \( j=0,\ldots,n-1\), *(get_a()+j) is a random access iterator for column \( j\).

◆ get_b()

B_iterator NonnegativeQuadraticProgram::get_b ( ) const

returns an iterator over the entries of \( \qpb\).

The corresponding past-the-end iterator is get_b()+get_m().

◆ get_c()

C_iterator NonnegativeQuadraticProgram::get_c ( ) const

returns an iterator over the entries of \( \qpc\).

The corresponding past-the-end iterator is get_c()+get_n().

◆ get_d()

D_iterator NonnegativeQuadraticProgram::get_d ( ) const

returns an iterator over the rows of \( 2D\).

The corresponding past-the-end iterator is get_d()+get_n(). For \( i=0,\ldots,n-1\), *(get_d()+i) is a random access iterator for the entries in row \( i\) below or on the diagonal. The valid range of this iterator is guaranteed to have length \( i+1\) but not more. Values to the right of the diagonal are deduced from the symmetry requirement on \( D\).

◆ get_r()

R_iterator NonnegativeQuadraticProgram::get_r ( ) const

returns an iterator over the entries of \( \qprel\).

The corresponding past-the-end iterator is get_r()+get_m(). The value CGAL::SMALLER stands for \( \leq\), CGAL::EQUAL stands for \( =\), and CGAL::LARGER stands for \( \geq\).