org.matheclipse.core.eval.interfaces

Class AbstractEvaluator

java.lang.Object

org.matheclipse.core.eval.interfaces.AbstractEvaluator

All Implemented Interfaces:

IFunctionEvaluator, IEvaluator

Direct Known Subclasses:

AbstractFunctionEvaluator, ChessboardDistance, ComplexExpand, ComposeList, Conjugate, ConstantArray, ContinuedFraction, Denominator, EuclidianDistance, FrobeniusSolve, FromContinuedFraction, Gather, HarmonicNumber, Im, InterpolatingFunction, InterpolatingPolynomial, ManhattanDistance, Negative, NonNegative, Norm, Normalize, Numerator, Plot, Plot3D, Positive, Range, Re, Replace, ReplaceAll, ReplaceList, ReplacePart, ReplaceRepeated, Select, Sign, SignCmp, SquaredEuclidianDistance, Timing, Tr, Transpose, TrigExpand, TrigReduce, TrigToExp, UnitStep

public abstract class AbstractEvaluator
extends java.lang.Object
implements IFunctionEvaluator

Abstract interface for built-in Symja functions. The numericEval() method delegates to the evaluate()

Constructor Summary

Constructors

Constructor and Description
AbstractEvaluator()

Method Summary

Modifier and Type	Method and Description
abstract IExpr	evaluate(IAST ast, EvalEngine engine) Symbolic evaluation of a function.
IExpr	numericEval(IAST ast, EvalEngine engine) Numeric evaluation of a function.
void	setUp(ISymbol symbol) Evaluate built-in rules and define Attributes for a function.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractEvaluator

public AbstractEvaluator()

Method Detail

numericEval

public IExpr numericEval(IAST ast,
                         EvalEngine engine)

Numeric evaluation of a function. ast.get(0) (or alternatively ast.head()) contains the head (i.e. the function symbol) of this abstract syntax tree (AST).
From ast.arg1() to ast.get(n) the ast contains the first to n-th argument of the function (alternatively you get the first to fifth argument with the methods arg1(), arg2(),... arg5()).
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:

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

engine - the users current evaluation engine

Returns:

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

See Also:

Validate, IExpr.head(), IAST.arg1(), IAST.arg2(), IAST.arg3()

setUp

public void setUp(ISymbol symbol)
           throws SyntaxError

Evaluate built-in rules and define Attributes for a function.

Specified by:

setUp in interface IEvaluator

Parameters:

symbol - the symbol which should be set up

Throws:

SyntaxError

evaluate

public abstract IExpr evaluate(IAST ast,
                               EvalEngine engine)

Symbolic evaluation of a function. ast.get(0) (or alternatively ast.head()) contains the head (i.e. the function symbol) of this abstract syntax tree (AST).
From ast.arg1() to ast.get(n) the ast contains the first to n-th argument of the function (alternatively you get the first to fifth argument with the methods arg1(), arg2(),... arg5()).
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

engine - the users current evaluation engine

Returns:

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

See Also:

Validate, IExpr.head(), IAST.arg1(), IAST.arg2(), IAST.arg3()