Class FunctionUtils

Method Details

• compose

  public static UnivariateFunction compose(UnivariateFunction... f)

  Composes functions.

  The functions in the argument list are composed sequentially, in the given order. For example, compose(f1,f2,f3) acts like f1(f2(f3(x))).

  Parameters:

  f - List of functions.

  Returns:

  the composite function.

• compose

  public static UnivariateDifferentiableFunction compose(UnivariateDifferentiableFunction... f)

  Composes functions.

  The functions in the argument list are composed sequentially, in the given order. For example, compose(f1,f2,f3) acts like f1(f2(f3(x))).

  Parameters:

  f - List of functions.

  Returns:

  the composite function.

  Since:

  3.1

• compose

  @Deprecated public static DifferentiableUnivariateFunction compose(DifferentiableUnivariateFunction... f)

  Deprecated.

  as of 3.1 replaced by compose(UnivariateDifferentiableFunction...)

  Composes functions.

  The functions in the argument list are composed sequentially, in the given order. For example, compose(f1,f2,f3) acts like f1(f2(f3(x))).

  Parameters:

  f - List of functions.

  Returns:

  the composite function.

• add

  public static UnivariateFunction add(UnivariateFunction... f)

  Adds functions.

  Parameters:

  f - List of functions.

  Returns:

  a function that computes the sum of the functions.

• add

  public static UnivariateDifferentiableFunction add(UnivariateDifferentiableFunction... f)

  Adds functions.

  Parameters:

  f - List of functions.

  Returns:

  a function that computes the sum of the functions.

  Since:

  3.1

• add

  @Deprecated public static DifferentiableUnivariateFunction add(DifferentiableUnivariateFunction... f)

  Deprecated.

  as of 3.1 replaced by add(UnivariateDifferentiableFunction...)

  Adds functions.

  Parameters:

  f - List of functions.

  Returns:

  a function that computes the sum of the functions.

• multiply

  public static UnivariateFunction multiply(UnivariateFunction... f)

  Multiplies functions.

  Parameters:

  f - List of functions.

  Returns:

  a function that computes the product of the functions.

• multiply

  public static UnivariateDifferentiableFunction multiply(UnivariateDifferentiableFunction... f)

  Multiplies functions.

  Parameters:

  f - List of functions.

  Returns:

  a function that computes the product of the functions.

  Since:

  3.1

• multiply

  @Deprecated public static DifferentiableUnivariateFunction multiply(DifferentiableUnivariateFunction... f)

  Deprecated.

  as of 3.1 replaced by multiply(UnivariateDifferentiableFunction...)

  Multiplies functions.

  Parameters:

  f - List of functions.

  Returns:

  a function that computes the product of the functions.

• combine

  public static UnivariateFunction combine(BivariateFunction combiner, UnivariateFunction f, UnivariateFunction g)

  Returns the univariate function h(x) = combiner(f(x), g(x)).

  Parameters:

  combiner - Combiner function.

  f - Function.

  g - Function.

  Returns:

  the composite function.

• collector

  public static MultivariateFunction collector(BivariateFunction combiner, UnivariateFunction f, double initialValue)

  Returns a MultivariateFunction h(x[]) defined by

   
   h(x[]) = combiner(...combiner(combiner(initialValue,f(x[0])),f(x[1]))...),f(x[x.length-1]))
   

  Parameters:

  combiner - Combiner function.

  f - Function.

  initialValue - Initial value.

  Returns:

  a collector function.

• collector

  public static MultivariateFunction collector(BivariateFunction combiner, double initialValue)

  Returns a MultivariateFunction h(x[]) defined by

   
   h(x[]) = combiner(...combiner(combiner(initialValue,x[0]),x[1])...),x[x.length-1])
   

  Parameters:

  combiner - Combiner function.

  initialValue - Initial value.

  Returns:

  a collector function.

• fix1stArgument

  public static UnivariateFunction fix1stArgument(BivariateFunction f, double fixed)

  Creates a unary function by fixing the first argument of a binary function.

  Parameters:

  f - Binary function.

  fixed - value to which the first argument of f is set.

  Returns:

  the unary function h(x) = f(fixed, x)

• fix2ndArgument

  public static UnivariateFunction fix2ndArgument(BivariateFunction f, double fixed)

  Creates a unary function by fixing the second argument of a binary function.

  Parameters:

  f - Binary function.

  fixed - value to which the second argument of f is set.

  Returns:

  the unary function h(x) = f(x, fixed)

• sample

  public static double[] sample(UnivariateFunction f, double min, double max, int n) throws NumberIsTooLargeException, NotStrictlyPositiveException

  Samples the specified univariate real function on the specified interval.

  The interval is divided equally into n sections and sample points are taken from min to max - (max - min) / n; therefore f is not sampled at the upper bound max.

  Parameters:

  f - Function to be sampled

  min - Lower bound of the interval (included).

  max - Upper bound of the interval (excluded).

  n - Number of sample points.

  Returns:

  the array of samples.

  Throws:

  NumberIsTooLargeException - if the lower bound min is greater than, or equal to the upper bound max.

  NotStrictlyPositiveException - if the number of sample points n is negative.

• toDifferentiableUnivariateFunction

  @Deprecated public static DifferentiableUnivariateFunction toDifferentiableUnivariateFunction(UnivariateDifferentiableFunction f)

  Deprecated.

  this conversion method is temporary in version 3.1, as the DifferentiableUnivariateFunction interface itself is deprecated

  Convert a UnivariateDifferentiableFunction into a DifferentiableUnivariateFunction.

  Parameters:

  f - function to convert

  Returns:

  converted function

• toUnivariateDifferential

  @Deprecated public static UnivariateDifferentiableFunction toUnivariateDifferential(DifferentiableUnivariateFunction f)

  Deprecated.

  this conversion method is temporary in version 3.1, as the DifferentiableUnivariateFunction interface itself is deprecated

  Convert a DifferentiableUnivariateFunction into a UnivariateDifferentiableFunction.

  Note that the converted function is able to handle DerivativeStructure up to order one. If the function is called with higher order, a NumberIsTooLargeException is thrown.

  Parameters:

  f - function to convert

  Returns:

  converted function

• toDifferentiableMultivariateFunction

  @Deprecated public static DifferentiableMultivariateFunction toDifferentiableMultivariateFunction(MultivariateDifferentiableFunction f)

  Deprecated.

  this conversion method is temporary in version 3.1, as the DifferentiableMultivariateFunction interface itself is deprecated

  Convert a MultivariateDifferentiableFunction into a DifferentiableMultivariateFunction.

  Parameters:

  f - function to convert

  Returns:

  converted function

• toMultivariateDifferentiableFunction

  @Deprecated public static MultivariateDifferentiableFunction toMultivariateDifferentiableFunction(DifferentiableMultivariateFunction f)

  Deprecated.

  this conversion method is temporary in version 3.1, as the DifferentiableMultivariateFunction interface itself is deprecated

  Convert a DifferentiableMultivariateFunction into a MultivariateDifferentiableFunction.

  Note that the converted function is able to handle DerivativeStructure elements that all have the same number of free parameters and order, and with order at most 1. If the function is called with inconsistent numbers of free parameters or higher order, a DimensionMismatchException or a NumberIsTooLargeException will be thrown.

  Parameters:

  f - function to convert

  Returns:

  converted function

• toDifferentiableMultivariateVectorFunction

  @Deprecated public static DifferentiableMultivariateVectorFunction toDifferentiableMultivariateVectorFunction(MultivariateDifferentiableVectorFunction f)

  Deprecated.

  this conversion method is temporary in version 3.1, as the DifferentiableMultivariateVectorFunction interface itself is deprecated

  Convert a MultivariateDifferentiableVectorFunction into a DifferentiableMultivariateVectorFunction.

  Parameters:

  f - function to convert

  Returns:

  converted function

• toMultivariateDifferentiableVectorFunction

  @Deprecated public static MultivariateDifferentiableVectorFunction toMultivariateDifferentiableVectorFunction(DifferentiableMultivariateVectorFunction f)

  Deprecated.

  this conversion method is temporary in version 3.1, as the DifferentiableMultivariateFunction interface itself is deprecated

  Convert a DifferentiableMultivariateVectorFunction into a MultivariateDifferentiableVectorFunction.

  Note that the converted function is able to handle DerivativeStructure elements that all have the same number of free parameters and order, and with order at most 1. If the function is called with inconsistent numbers of free parameters or higher order, a DimensionMismatchException or a NumberIsTooLargeException will be thrown.

  Parameters:

  f - function to convert

  Returns:

  converted function