IlcGranularFunction

An instance of IlcGranularFunction holds a description of a granular step-wise function.

The granular function must respect the following properties:

It is defined over the range [xmin,xmax), and takes only integer values.
It consists only of steps with non-negative values. These steps are closed on the left and open on the right.
Its maximum value multiplied by the width xmax-xmin of its definition interval must remain in the range [0,IlcIntMax), in order to not overflow the platform integer representation.

These properties are checked when starting to solve the problem, and an exception will be thrown if necessary.

The positive granularity parameter is used as a scaling factor when computing the integral of the function. This allows limited representation of non-integer function values. This is particularly the case for integral expressions or constraints built with IlcGranularFunction (see Functional and Integral Constraints on Resources for more information).

When computing the integral of the function over a given interval (for example, the start and end time of an activity), the result is divided by the granularity, and the result rounded:

Four rounding modes are available when dividing by granularity. See Functional and Integral Constraints on Resources for more information.

Note that the member function IlcGranularFunction::getValue does not use the granularity, but returns the actual value stored in the function, without any scaling.

For more information, see Functional and Integral Constraints on Resources.

Constructor Summary
`public`	`IlcGranularFunction()`
`public`	`IlcGranularFunction(IlcGranularFunctionI * impl)`
`public`	`IlcGranularFunction(IlcManager m, IlcInt xmin, IlcInt xmax, IlcInt granularity=1, IlcGranularFunctionRoundingMode rounding=IlcGranularFunctionRoundUpward)`

Method Summary
`public void`	`close() const`
`public IlcInt`	`getDefinitionIntervalMax() const`
`public IlcInt`	`getDefinitionIntervalMin() const`
`public IlcInt`	`getGranularity() const`
`public IlcGranularFunctionI *`	`getImpl() const`
`public const char *`	`getName() const`
`public IlcAny`	`getObject() const`
`public IlcGranularFunctionRoundingMode`	`getRoundingMode() const`
`public IloSolver`	`getSolver() const`
`public IloSolverI *`	`getSolverI() const`
`public IlcInt`	`getValue(IlcInt x) const`
`public IlcBool`	`isClosed() const`
`public IlcIntExp`	`operator()(const IlcIntVar x) const`
`public void`	`operator=(const IlcGranularFunction & h)`
`public void`	`setName(const char * name) const`
`public void`	`setObject(IlcAny object) const`
`public void`	`setRoundingMode(IlcGranularFunctionRoundingMode rounding) const`
`public void`	`setValue(IlcInt x1, IlcInt x2, IlcInt value) const`

IlcGranularFunction

This constructor creates an empty handle. You must initialize it before you use it.

IlcGranularFunction

This constructor creates a handle object from a pointer to an implementation object.

IlcGranularFunction

This constructor creates a new instance of IlcGranularFunction, with granularity equal to granularity. The initial function is on the interval [xmin, xmax), and will be set to a constant initial value of granularity over this interval. The parameter rounding selects the default rounding mode applicable for an integral constraint built with this instance.

This member function closes the invoking function. That is, it states that the function is known so constraint propagation can proceed. This is a reversible operation. Any modification of a closed function will raise an error.

getDefinitionIntervalMax

This member function returns the right-most point of the interval of definition of the invoking granular function.

getDefinitionIntervalMin

This member function returns the left-most point of the interval of definition of the invoking granular function.

getGranularity

This member function returns the value of the granularity.

getImpl

This constructor creates an object by copying another one. This constructor creates an object by copying another one. This member function returns a pointer to the implementation object of the invoking handle.

getName

This member function returns the name of the invoking object.

getObject

This member function returns a pointer to the external object associated with the invoking object, if there is such an association. It returns 0 (zero) otherwise.

getRoundingMode

This member function returns the current rounding mode of the invoking granular function.

getSolver

This member function returns an instance of IloSolver associated with the invoking object.

getSolverI

This member function returns a pointer to the implementation object of the solver where the invoking object was extracted.

getValue

This member function returns the current value of the granular function at point x. This point must be inside the range [xmin, xmax). Otherwise, an exception is thrown.

isClosed

This member function returns IlcTrue if the invoking object is closed. Otherwise, it returns IlcFalse.

operator()

This function creates and returns an integer expression constrained to be the value of the function at the value of variable x. The granularity of the function must be equal to 1, otherwise, an error will be raised.

operator=

This operator assigns an address to the handle pointer of the invoking object. That address is the location of the implementation object of the provided argument.

setName

This member function sets the name of the invoking object to a copy of name. This assignment is a reversible action.

setObject

This member function establishes a link between the invoking object and an external object of which the invoking object might be a data member.

setRoundingMode

This member function selects the rounding mode that will be used when creating an integral constraint with the invoking granular function.

setValue

This member function sets the value of the granular function to value over the interval [x1, x2). The IlcGranularFunction must not be closed. The arguments x1 and x2 must respect xmin <= x1 < x2 <= xmax, and value must be non-negative. Otherwise, an exception will be thrown.

Class IlcGranularFunction