ch.javasoft.util.numeric
Class Zero

java.lang.Object
  ch.javasoft.util.numeric.Zero

public class Zero
extends Object

Zero is a helper class treating values close to zero as zero. A tolerance or precision can be defined when constructing an instance of Zero.

Field Summary

static int	DEFAULT_PRECISION default precision 10, meaning 10 decimal places
static double	DEFAULT_TOLERANCE default precision 10-10, meaning 10 decimal places
static double	EPS_TOLERANCE normal machine precision for doubles, that is 2-52
int	mPrecision
double	mZeroNeg
double	mZeroPos

Constructor Summary

Zero()
Constructor using DEFAULT_PRECISION

Zero(double tolerance)
Constructor using the specified tolerance

Zero(int precision)
Constructor using the specified precision

Method Summary

boolean	isNegative(double value)
boolean	isNegPos(double valueA, double valueB)
boolean	isNonZero(double value)
boolean	isPositive(double value)
boolean	isZero(double value)
boolean	isZeroNeg(double value)
boolean	isZeroPos(double value)
double	roundZero(double value) If the given value is within the zero tolerance, zero is returned, and the given value otherwise.
int	sgn(double value)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PRECISION

public static final int DEFAULT_PRECISION

default precision 10, meaning 10 decimal places

See Also:

Constant Field Values

DEFAULT_TOLERANCE

public static final double DEFAULT_TOLERANCE

default precision 10^-10, meaning 10 decimal places

See Also:

Constant Field Values

EPS_TOLERANCE

public static final double EPS_TOLERANCE

normal machine precision for doubles, that is 2^-52

mPrecision

public final int mPrecision

mZeroPos

public final double mZeroPos

mZeroNeg

public final double mZeroNeg

Constructor Detail

Zero

public Zero()

Constructor using DEFAULT_PRECISION

Zero

public Zero(double tolerance)

Constructor using the specified tolerance

Parameters:

tolerance - a number close to zero, absolute values larger than the absolute value of tolerance are treated non-zero, other values as zero

Zero

public Zero(int precision)

Constructor using the specified precision

Parameters:

precision - the precision in decimal places, absolute values larger than 10-abs(precision) are treated non-zero, other values as zero

Method Detail

sgn

public int sgn(double value)

isZero

public boolean isZero(double value)

isNonZero

public boolean isNonZero(double value)

isZeroNeg

public boolean isZeroNeg(double value)

isZeroPos

public boolean isZeroPos(double value)

isNegative

public boolean isNegative(double value)

isPositive

public boolean isPositive(double value)

isNegPos

public boolean isNegPos(double valueA,
                        double valueB)

roundZero

public double roundZero(double value)

If the given value is within the zero tolerance, zero is returned, and the given value otherwise.