com.numericalmethod.suanshu.optimization.constrained.integer.linear.problem

Class ILPProblemImpl1

java.lang.Object

com.numericalmethod.suanshu.optimization.constrained.integer.linear.problem.ILPProblemImpl1

All Implemented Interfaces:

LPProblem, IPProblem, ILPProblem, ConstrainedOptimProblem, OptimProblem, java.io.Serializable

Direct Known Subclasses:

PureILPProblem

public class ILPProblemImpl1
extends java.lang.Object
implements ILPProblem

This implementation is an ILP problem, in which the variables can be real or integral.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ILPProblemImpl1(Vector cost, LinearGreaterThanConstraints greater, LinearLessThanConstraints less, LinearEqualityConstraints equal, BoxConstraints bounds, int[] integers, double epsilon) Construct an ILP problem, in which the variables can be real or integral.

Method Summary

Modifier and Type	Method and Description
ImmutableMatrix	A() Get the coefficients, A, of the greater-than-or-equal-to constraints A * x ≥ b.
ImmutableMatrix	Aeq() Get the coefficients, Aeq, of the equality constraints Aeq * x ≥ beq.
ImmutableVector	b() Get the values, b, of the greater-than-or-equal-to constraints A * x ≥ b.
ImmutableVector	beq() Get the values, beq, of the equality constraints Aeq * x ≥ beq.
ImmutableVector	c() Get the objective function.
int	dimension() Get the number of variables.
double	epsilon() Get the threshold to check whether a variable is an integer.
RealScalarFunction	f() Get the objective function.
LinearEqualityConstraints	getEqualityConstraints() Get the equality constraints, hi(x) = 0
int[]	getIntegerIndices() Get the indices of the integral variables.
LinearLessThanConstraints	getLessThanConstraints() Get the less-than-or-equal-to constraints, gi(x) ≤ 0
int[]	getNonIntegralIndices(double[] x) Check which elements in x do not satisfy the integral constraints.
boolean	isFree(int i) Check whether xi is a free variable after handling the box constraints.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ILPProblemImpl1

public ILPProblemImpl1(Vector cost,
                       LinearGreaterThanConstraints greater,
                       LinearLessThanConstraints less,
                       LinearEqualityConstraints equal,
                       BoxConstraints bounds,
                       int[] integers,
                       double epsilon)

Construct an ILP problem, in which the variables can be real or integral.

Parameters:

cost - the linear objective function

greater - the greater-than-or-equal-to constraints

less - the less-than-or-equal-to constraints

equal - the equality constraints

bounds - the box constraints

integers - the indices of the integral variables

epsilon - a precision parameter: when a number |x| ≤ ε, it is considered 0

Method Detail

epsilon

public double epsilon()

Description copied from interface: IPProblem

Get the threshold to check whether a variable is an integer.

Specified by:

epsilon in interface IPProblem

Returns:

the precision parameter: when a number |x| ≤ ε, it is considered 0

getIntegerIndices

public int[] getIntegerIndices()

Description copied from interface: IPProblem

Get the indices of the integral variables.

Specified by:

getIntegerIndices in interface IPProblem

Returns:

the integral variable indices

getNonIntegralIndices

public int[] getNonIntegralIndices(double[] x)

Description copied from interface: IPProblem

Check which elements in x do not satisfy the integral constraints. The indices count from 1.

Specified by:

getNonIntegralIndices in interface IPProblem

Parameters:

x - an argument to the objective function

Returns:

the set of indices of values in x that do not satisfy the integral constraints. An int[] of length 0 indicates that all integral variables in x are integers.

getLessThanConstraints

public LinearLessThanConstraints getLessThanConstraints()

Description copied from interface: ConstrainedOptimProblem

Get the less-than-or-equal-to constraints, g_i(x) ≤ 0

Specified by:

getLessThanConstraints in interface ConstrainedOptimProblem

Returns:

the less-than-or-equal-to constraints

getEqualityConstraints

public LinearEqualityConstraints getEqualityConstraints()

Description copied from interface: ConstrainedOptimProblem

Get the equality constraints, h_i(x) = 0

Specified by:

getEqualityConstraints in interface ConstrainedOptimProblem

Returns:

the equality constraints

dimension

public int dimension()

Description copied from interface: OptimProblem

Get the number of variables.

Specified by:

dimension in interface OptimProblem

Returns:

the number of variables.

f

public RealScalarFunction f()

Description copied from interface: OptimProblem

Get the objective function.

Specified by:

f in interface OptimProblem

Returns:

the objective function

c

public ImmutableVector c()

Description copied from interface: LPProblem

Get the objective function.

Specified by:

c in interface LPProblem

Returns:

the objective function

A

public ImmutableMatrix A()

Description copied from interface: LPProblem

Get the coefficients, A, of the greater-than-or-equal-to constraints A * x ≥ b.

Specified by:

A in interface LPProblem

Returns:

the coefficients of the greater-than-or-equal-to constraints

b

public ImmutableVector b()

Description copied from interface: LPProblem

Get the values, b, of the greater-than-or-equal-to constraints A * x ≥ b.

Specified by:

b in interface LPProblem

Returns:

the values of the greater-than-or-equal-to constraints

Aeq

public ImmutableMatrix Aeq()

Description copied from interface: LPProblem

Get the coefficients, Aeq, of the equality constraints Aeq * x ≥ beq.

Specified by:

Aeq in interface LPProblem

Returns:

the coefficients of the equality constraints

beq

public ImmutableVector beq()

Description copied from interface: LPProblem

Get the values, beq, of the equality constraints Aeq * x ≥ beq.

Specified by:

beq in interface LPProblem

Returns:

the values of the equality constraints

isFree

public boolean isFree(int i)

Description copied from interface: LPProblem

Check whether x_i is a free variable after handling the box constraints.

Specified by:

isFree in interface LPProblem

Parameters:

i - the index of a variable, counting from 1

Returns:

true if x_i is free