Package com.singularsys.jep.functions

Class Power

java.lang.Object

com.singularsys.jep.functions.PostfixMathCommand

com.singularsys.jep.functions.BinaryFunction

com.singularsys.jep.functions.Power

All Implemented Interfaces:

PostfixMathCommandI, RealBinaryFunction, Serializable

Direct Known Subclasses:

BigDecPow

public class Power
extends BinaryFunction
implements RealBinaryFunction

Computes the power of a number. Implements a fast algorithm for integer powers by Patricia Shanahan [email protected].

Since:

3.3 Returns NaN rather than throwing and exception for out of range real arguments

Author:

N Funk, R Morris, Patricia Shanahan

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	strict

Fields inherited from class com.singularsys.jep.functions.PostfixMathCommand

curNumberOfParameters, name, NaN, numberOfParameters

Constructor Summary

Constructors

Constructor	Description
Power()	Standard constructor, Complex results for x < 0, y non integral.
Power(boolean strict)	If strict is true then returns NaN for x < 0, y non-integral.

Method Summary

Modifier and Type	Method	Description
Object	eval(Object l, Object r)
double	evaluate(double l, double r)
boolean	isAllowComplexResults()	Whether complex results are allowed for number arguments.
static double	power(double l, int n)	A fast routine for computing integer powers.
static Object	power(Complex c1, Complex c2)
static Object	power(Complex c, Number d)
static Object	power(Number d, Complex c)
Object	power(Number d1, Number d2)
Object	power(Object param1, Object param2)
void	setAllowComplexResults(boolean allowComplexResults)

Methods inherited from class com.singularsys.jep.functions.BinaryFunction

instanceOf, instanceOf, run

Methods inherited from class com.singularsys.jep.functions.PostfixMathCommand

asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, checkNumberOfParameters, getName, getNumberOfParameters, setCurNumberOfParameters, setName, toString, toString

Methods inherited from class java.lang.Object

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

Field Details

strict

protected boolean strict

Constructor Details

Power

public Power()

Standard constructor, Complex results for x < 0, y non integral.

Power

public Power(boolean strict)

If strict is true then returns NaN for x < 0, y non-integral.

Parameters:

strict - true to force real results

Method Details

eval

public Object eval(Object l,
 Object r)
            throws EvaluationException

Specified by:

eval in class BinaryFunction

Throws:

EvaluationException

power

public Object power(Object param1,
 Object param2)
             throws EvaluationException

Throws:

EvaluationException

power

public Object power(Number d1,
 Number d2)

power

public static Object power(Complex c1,
 Complex c2)

power

public static Object power(Complex c,
 Number d)

power

public static Object power(Number d,
 Complex c)

power

public static double power(double l,
 int n)

A fast routine for computing integer powers. Code adapted from efficient power by Patricia Shanahan [email protected] Almost identical to the method Knuth gives on page 462 of The Art of Computer Programming Volume 2 Seminumerical Algorithms.

Parameters:

l - number to be taken to a power.

n - power

Returns:

x to the power n

evaluate

public double evaluate(double l,
 double r)

Specified by:

evaluate in interface RealBinaryFunction

isAllowComplexResults

public boolean isAllowComplexResults()

Whether complex results are allowed for number arguments. If l is a negative Number and r is non-integral Number then the pow function typically returns a Complex result. If this flag is set then an EvaluationException would be thrown instead.

Returns:

the status of the allowComplexResults flag.

setAllowComplexResults

public void setAllowComplexResults(boolean allowComplexResults)