org.matheclipse.core.reflection.system

Class Cancel

java.lang.Object

org.matheclipse.core.eval.interfaces.AbstractFunctionEvaluator

org.matheclipse.core.reflection.system.Cancel

All Implemented Interfaces:

IFunctionEvaluator, IEvaluator

public class Cancel
extends AbstractFunctionEvaluator

Cancel(expr) - cancels out common factors in numerators and denominators.

Constructor Summary

Constructors

Constructor and Description
Cancel()

Method Summary

Modifier and Type	Method and Description
static IExpr[]	cancelGCD(IExpr poly1, IExpr poly2) Calculate the 3 element result array [ commonFactor, poly1.divide(gcd(poly1, poly2)), poly2.divide(gcd(poly1, poly2)) ] for the given expressions poly1 and poly2.
static IExpr	cancelPowerTimes(IExpr powerTimesAST)
IExpr	evaluate(IAST ast) Symbolic evaluation of a function.
void	setUp(ISymbol symbol) Evaluate built-in rules and define Attributes for a function.

Methods inherited from class org.matheclipse.core.eval.interfaces.AbstractFunctionEvaluator

createRuleFromMethod, getPeriodicParts, getPureImaginaryPart, getRuleAST, isNegativeExpression, numericEval

Methods inherited from class java.lang.Object

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

Constructor Detail

Cancel

public Cancel()

Method Detail

evaluate

public IExpr evaluate(IAST ast)

Description copied from class: AbstractFunctionEvaluator

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

Specified by:

evaluate in class AbstractFunctionEvaluator

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

cancelPowerTimes

public static IExpr cancelPowerTimes(IExpr powerTimesAST)
                              throws JASConversionException

Parameters:

powerTimesAST - an Times[...] or Power[...] AST, where common factors should be canceled out.

Returns:

Throws:

JASConversionException

cancelGCD

public static IExpr[] cancelGCD(IExpr poly1,
                                IExpr poly2)
                         throws JASConversionException

Calculate the 3 element result array [ commonFactor, poly1.divide(gcd(poly1, poly2)), poly2.divide(gcd(poly1, poly2)) ] for the given expressions poly1 and poly2.

Parameters:

poly1 - a BigRational polynomial which could be converted to JAS polynomial

poly2 - a BigRational polynomial which could be converted to JAS polynomial

Returns:

null if the expressions couldn't be converted to JAS polynomials

Throws:

JASConversionException

setUp

public void setUp(ISymbol symbol)
           throws SyntaxError

Description copied from class: AbstractFunctionEvaluator

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

Specified by:

setUp in interface IEvaluator

Overrides:

setUp in class AbstractFunctionEvaluator

Parameters:

symbol - the symbol which should be set up

Throws:

SyntaxError