org.apache.commons.geometry.core.precision

Class EpsilonDoublePrecisionContext

java.lang.Object

org.apache.commons.geometry.core.precision.DoublePrecisionContext

org.apache.commons.geometry.core.precision.EpsilonDoublePrecisionContext

All Implemented Interfaces:

Serializable, Comparator<Double>

public class EpsilonDoublePrecisionContext
extends DoublePrecisionContext
implements Serializable

Simple DoublePrecisionContext subclass that uses an absolute epsilon value to determine equality between doubles.

This class uses the Precision.compareTo(double, double, double) method to compare numbers. Two values are considered equal if there is no floating point value strictly between them or if their numerical difference is less than or equal to the configured epsilon value.

See Also:

Precision.compareTo(double, double, double), Serialized Form

Constructor Summary

Constructors

Constructor and Description
EpsilonDoublePrecisionContext(double eps) Simple constructor.

Method Summary

Modifier and Type	Method and Description
int	compare(double a, double b) Compare two double values.
boolean	equals(Object obj)
double	getEpsilon() Get the epsilon value for the instance.
double	getMaxZero() Get the largest positive double value that is still considered equal to zero by this instance.
int	hashCode()
String	toString()

Methods inherited from class org.apache.commons.geometry.core.precision.DoublePrecisionContext

compare, eq, eqZero, gt, gte, lt, lte, sign

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

EpsilonDoublePrecisionContext

public EpsilonDoublePrecisionContext(double eps)

Simple constructor.

Parameters:

eps - Epsilon value. Numbers are considered equal if there is no floating point value strictly between them or if their difference is less than or equal to this value.

Throws:

IllegalArgumentException - if the given epsilon value is infinite, NaN, or negative

Method Detail

getEpsilon

public double getEpsilon()

Get the epsilon value for the instance. Numbers are considered equal if there is no floating point value strictly between them or if their difference is less than or equal to this value.

Returns:

the epsilon value for the instance

getMaxZero

public double getMaxZero()

Get the largest positive double value that is still considered equal to zero by this instance. This value is equal to the epsilon value for the instance.

Specified by:

getMaxZero in class DoublePrecisionContext

Returns:

the largest positive double value still considered equal to zero

See Also:

getEpsilon()

compare

public int compare(double a,
                   double b)

Compare two double values. The returned value is

• 0 if the arguments are considered equal,
• -1 if a < b,
• +1 if a > b or if either value is NaN.

Specified by:

compare in class DoublePrecisionContext

Parameters:

a - first value

b - second value

Returns:

0 if the values are considered equal, -1 if the first is smaller than the second, 1 is the first is larger than the second or either value is NaN.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Specified by:

equals in interface Comparator<Double>

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object