ilog.concert

Interface IloNumToNumSegmentFunction

public interface IloNumToNumSegmentFunction

Piecewise linear function over a segment.

An instance of IloNumToNumSegmentFunction represents a piecewise linear function that is defined everywhere on an interval [xMin, xMax). Each interval [x1, x2) on which the function is linear is called a segment.

Furthermore, when two consecutive segments of the function are co-linear, these segments are merged so that the function is always represented with the minimal number of segments.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(IloNumToNumSegmentFunction fct) This operator adds the argument function fct to the invoking piecewise linear function.
void	addValue(double x1, double x2, double v) This member function adds v to the value of the invoking piecewise linear function everywhere on the interval [x1,x2).
IloNumToNumSegmentFunction	copy() This member function creates and returns a new function that is a copy of the invoking function.
void	dilate(double k) This member function multiplies by k the scale of x for the invoking piecewise linear function.
double	getArea(double x1, double x2) This member function returns the area of the invoking piecewise linear function on the interval [x1,x2).
double	getDefinitionIntervalMax() This member function returns the right-most point of the definition interval of the invoking piecewise linear function.
double	getDefinitionIntervalMin() This member function returns the left-most point of the definition interval of the invoking piecewise linear function.
double	getMax(double x1, double x2) This member function returns the maximal value of the invoking piecewise linear function on the interval [x1,x2).
double	getMin(double x1, double x2) This member function returns the minimal value of the invoking piecewise linear function on the interval [x1,x2).
double	getValue(double x) This member function returns the value of the function at point x.
void	prod(double k) This operator multiplies by a factor k the value of the invoking piecewise linear function everywhere on the definition interval.
void	setMax(double x1, double x2, double v) This member function sets the value of the invoking piecewise linear function to be the maximum between the current value and v everywhere on the interval [x1,x2).
void	setMax(double x1, double v1, double x2, double v2) This member function sets the value of the invoking piecewise linear function to be the maximum between the current value and the value of the linear function: x --> v1 + (x-x1)*(v2-v1)/(x2-x1) everywhere on the interval [x1, x2).
void	setMax(IloNumToNumSegmentFunction fct) This member function sets the value of the invoking piecewise linear function to be the maximum between the current value and the value of fct everywhere on the definition interval of the invoking function.
void	setMin(double x1, double x2, double v) This member function sets the value of the invoking piecewise linear function to be the minimum between the current value and v everywhere on the interval [x1,x2).
void	setMin(double x1, double v1, double x2, double v2) This member function sets the value of the invoking piecewise linear function to be the minimum between the current value and the value of the linear function: x --> v1 + (x-x1)*(v2-v1)/(x2-x1) everywhere on the interval [x1,x2).
void	setMin(IloNumToNumSegmentFunction fct) This member function sets the value of the invoking piecewise linear function to be the minimum between the current value and the value of fct everywhere on the definition interval of the invoking function.
void	setPeriodic(IloNumToNumSegmentFunction f, double x0, double n, double dval) This member function initializes the invoking function as a piecewise linear function that repeats the piecewise linear function f, n times after x0.
void	setPeriodicValue(double x1, double x2, IloNumToNumSegmentFunction f, double offset) This member function changes the value of the invoking function on the interval [x1,x2).
void	setPoints(ilog.concert.IloNumArray x, ilog.concert.IloNumArray v) This member function initializes the invoking function as a piecewise linear function whose segments are defined by the two argument arrays x and v.
void	setSlope(double x1, double x2, double v, double slope) This member function sets the value of the invoking piecewise linear function equal to f, associating for each x in [x1,x2) -> f(x) = v + slope * (x-x1).
void	setValue(double x1, double x2, double v) This member function sets the value of the invoking piecewise linear function to beant and equal to v on the interval [x1,x2).
void	shift(double dx, double dval) This member function shifts the invoking function from dx to the right if dx > 0 or -dx to the left if dx < 0.
void	sub(IloNumToNumSegmentFunction fct) This operator subtracts the argument function fct from the invoking piecewise linear function.

Method Detail

setSlope

void setSlope(double x1,
            double x2,
            double v,
            double slope)

This member function sets the value of the invoking piecewise linear function equal to f, associating for each x in [x1,x2) -> f(x) = v + slope * (x-x1).

setValue

void setValue(double x1,
            double x2,
            double v)

This member function sets the value of the invoking piecewise linear function to beant and equal to v on the interval [x1,x2).

copy

IloNumToNumSegmentFunction copy()

This member function creates and returns a new function that is a copy of the invoking function.

setPeriodic

void setPeriodic(IloNumToNumSegmentFunction f,
               double x0,
               double n,
               double dval)

This member function initializes the invoking function as a piecewise linear function that repeats the piecewise linear function f, n times after x0. More precisely, if f is defined on [xfpMin,xfpMax) and if the invoking function is defined on [xMin,xMax), the value of the invoking function will be:

• dval on [xMin, x0),
• f((x-x0+xfpMin) % (xfpMax-xfpMin)) for x in [x0, Min(x0+n*(xfpMax-xfpMin), xMax)), and
• dval on [Min(x0+n*(xfpMax-xfpMin), xMax), xMax)

setPeriodicValue

void setPeriodicValue(double x1,
                    double x2,
                    IloNumToNumSegmentFunction f,
                    double offset)

This member function changes the value of the invoking function on the interval [x1,x2). On this interval, the invoking function is set to equal a repetition of the pattern function f with an initial offset of offset. The invoking function is not modified outside the interval [x1,x2). More precisely, if [min,max) denotes the definition interval of f, for all t in [x1,x2), the invoking function at t is set to equal f(min + (offset+t-x1)%(max-min))) where % denotes the modulo operator. By default, the offset is equal to 0.

setPoints

void setPoints(ilog.concert.IloNumArray x,
             ilog.concert.IloNumArray v)

This member function initializes the invoking function as a piecewise linear function whose segments are defined by the two argument arrays x and v.

More precisely, the size n of array x must be equal to the size of array v, and if the created function is defined on the interval [xmin,xmax), its values will be:

• v[0] on interval [xmin, x[0]),
• v[i] + (t-x[i])*(v[i+1]-v[i])/(x[i+1]-x[i]) for t in [x[i], x[i+1]) for all i in [0, n-2] such that x[i-1] ≠ x[i], and
• v[n-1] on interval [x[n-1],xmax).

addValue

void addValue(double x1,
            double x2,
            double v)

This member function adds v to the value of the invoking piecewise linear function everywhere on the interval [x1,x2).

setMax

void setMax(double x1,
          double x2,
          double v)

This member function sets the value of the invoking piecewise linear function to be the maximum between the current value and v everywhere on the interval [x1,x2).

setMax

void setMax(double x1,
          double v1,
          double x2,
          double v2)

This member function sets the value of the invoking piecewise linear function to be the maximum between the current value and the value of the linear function:

x --> v1 + (x-x1)*(v2-v1)/(x2-x1) everywhere on the interval [x1, x2).

setMin

void setMin(double x1,
          double x2,
          double v)

This member function sets the value of the invoking piecewise linear function to be the minimum between the current value and v everywhere on the interval [x1,x2).

setMin

void setMin(double x1,
          double v1,
          double x2,
          double v2)

This member function sets the value of the invoking piecewise linear function to be the minimum between the current value and the value of the linear function:

x --> v1 + (x-x1)*(v2-v1)/(x2-x1) everywhere on the interval [x1,x2).

shift

void shift(double dx,
         double dval)

This member function shifts the invoking function from dx to the right if dx > 0 or -dx to the left if dx < 0. It has no effect if dx = 0. More precisely, if the invoking function is defined on [xMin,xMax) and dx > 0, the new value of the invoking function is:

• dval on the interval [xMin,xMin+dx),
• for all x in [xMin+dx,xMax), the former value at x-dx.

If dx < 0, the new value of the invoking function is:

• for all x in [xMin,xMax+dx), the former value at x-dx,
• dval on the interval [xMax+dx,xMax).

getDefinitionIntervalMin

double getDefinitionIntervalMin()

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

getDefinitionIntervalMax

double getDefinitionIntervalMax()

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

getValue

double getValue(double x)

This member function returns the value of the function at point x.

getMax

double getMax(double x1,
            double x2)

This member function returns the maximal value of the invoking piecewise linear function on the interval [x1,x2). An instance of IloException is thrown if the interval [x1,x2) is not included in the definition interval of the invoking function.

getMin

double getMin(double x1,
            double x2)

This member function returns the minimal value of the invoking piecewise linear function on the interval [x1,x2). An instance of IloException is thrown if the interval [x1,x2) is not included in the definition interval of the invoking function.

getArea

double getArea(double x1,
             double x2)

This member function returns the area of the invoking piecewise linear function on the interval [x1,x2). An instance of IloException is thrown if the interval [x1,x2) is not included in the definition interval of the invoking function.

prod

void prod(double k)

This operator multiplies by a factor k the value of the invoking piecewise linear function everywhere on the definition interval.

add

void add(IloNumToNumSegmentFunction fct)

This operator adds the argument function fct to the invoking piecewise linear function.

sub

void sub(IloNumToNumSegmentFunction fct)

This operator subtracts the argument function fct from the invoking piecewise linear function.

setMin

void setMin(IloNumToNumSegmentFunction fct)

This member function sets the value of the invoking piecewise linear function to be the minimum between the current value and the value of fct everywhere on the definition interval of the invoking function. The definition interval of fct must be the same as the one of the invoking piecewise linear function.

setMax

void setMax(IloNumToNumSegmentFunction fct)

This member function sets the value of the invoking piecewise linear function to be the maximum between the current value and the value of fct everywhere on the definition interval of the invoking function. The interval of definition of fct must be the same as that of the invoking piecewise linear function.

dilate

void dilate(double k)

This member function multiplies by k the scale of x for the invoking piecewise linear function. k must be a nonnegative numeric value. More precisely, if the invoking function was defined over an interval [xMin,xMax), it will be redefined over the interval [k*xMin,k*xMax) and the value at x will be the former value at x/k.