org.matheclipse.core.reflection.system

Class HarmonicNumber

java.lang.Object

org.matheclipse.core.reflection.system.HarmonicNumber

All Implemented Interfaces:

IFunctionEvaluator, IEvaluator

public class HarmonicNumber
extends java.lang.Object
implements IFunctionEvaluator

Harmonic number of a given integer value See: Harmonic number

Constructor Summary

Constructors

Constructor and Description
HarmonicNumber()

Method Summary

Modifier and Type	Method and Description
IExpr	evaluate(IAST ast) Symbolic evaluation of a function.
BigFraction	harmonicNumber(int n) The Harmonic number at the index specified
IExpr	numericEval(IAST functionList) Numeric evaluation of a function.
void	setUp(ISymbol symbol) This method will be called every time a new ISymbol will be created.

Methods inherited from class java.lang.Object

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

Constructor Detail

HarmonicNumber

public HarmonicNumber()

Method Detail

evaluate

public IExpr evaluate(IAST ast)

Description copied from interface: IFunctionEvaluator

Symbolic evaluation of a function. ast.get(0) contains the head (i.e. the function symbol) of this abstract syntax tree (AST). ast.get(1) to ast.get(n) contains the first to n-th argument of the function.
If necessary use the methods from the Validate class to check the number or types of arguments in the evaluate method.
Note: if the symbolic evaluation isn't possible or no result is found the evaluate method returns with a null value without throwing an exception!

Specified by:

evaluate in interface IFunctionEvaluator

Parameters:

ast - the abstract syntax tree (AST) which should be evaluated

Returns:

the evaluated object or null, if evaluation isn't possible

See Also:

Validate

numericEval

public IExpr numericEval(IAST functionList)

Description copied from interface: IFunctionEvaluator

Numeric evaluation of a function. ast.get(0) contains the head (i.e. the function symbol) of this abstract syntax tree (AST). ast.get(1) to ast.get(n) contains the first to n-th argument of the function.
If necessary use the methods from the Validate class to check the number or types of arguments in the evaluate method.

Specified by:

numericEval in interface IFunctionEvaluator

Parameters:

functionList - the abstract syntax tree (AST) which should be evaluated

Returns:

the evaluated object or null, if evaluation isn't possible

See Also:

Validate

harmonicNumber

public BigFraction harmonicNumber(int n)

The Harmonic number at the index specified

Parameters:

n - the index, non-negative.

Returns:

the H_1=1 for n=1, H_2=3/2 for n=2 etc. For values of n less than 1, zero is returned.

setUp

public void setUp(ISymbol symbol)
           throws SyntaxError

Description copied from interface: IEvaluator

This method will be called every time a new ISymbol will be created. In this method you can set ISymbol attributes or constants for the symbol

Specified by:

setUp in interface IEvaluator

Parameters:

symbol - the symbol which should be set up

Throws:

SyntaxError