Package org.apache.commons.numbers.core

Enum Norm

java.lang.Object

java.lang.Enum<Norm>

org.apache.commons.numbers.core.Norm

All Implemented Interfaces:

Serializable, Comparable<Norm>

public enum Norm
extends Enum<Norm>

Norm functions.

The implementations provide increased numerical accuracy. Algorithms primary source is the 2005 paper Accurate Sum and Dot Product by Takeshi Ogita, Siegfried M. Rump, and Shin'ichi Oishi published in SIAM J. Sci. Comput.

Enum Constant Summary

Enum Constants

Enum Constant	Description
EUCLIDEAN	Alias for L2.
L1	Manhattan norm (sum of the absolute values of the arguments).
L2	Euclidean norm.
LINF	Maximum norm (maximum of the absolute values of the arguments).
MANHATTAN	Alias for L1.
MAXIMUM	Alias for LINF.

Method Summary

Modifier and Type	Method	Description
final double	of(double[] v)	Computes the norm.
final double	of(double x, double y)	Computes the norm.
final double	of(double x, double y, double z)	Computes the norm.
static Norm	valueOf(String name)	Returns the enum constant of this type with the specified name.
static Norm[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

L1

public static final Norm L1

Manhattan norm (sum of the absolute values of the arguments).

MANHATTAN

public static final Norm MANHATTAN

Alias for L1.

L2

public static final Norm L2

Euclidean norm.

EUCLIDEAN

public static final Norm EUCLIDEAN

Alias for L2.

LINF

public static final Norm LINF

Maximum norm (maximum of the absolute values of the arguments).

MAXIMUM

public static final Norm MAXIMUM

Alias for LINF.

Method Details

values

public static Norm[] values()

Returns an array containing the constants of this enum type, in the order they are declared.

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Norm valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

of

public final double of(double x,
 double y)

Computes the norm.

Special cases:

• If either value is Double.NaN, then the result is Double.NaN.
• If either value is infinite and the other value is not Double.NaN, then the result is Double.POSITIVE_INFINITY.

Parameters:

x - Argument.

y - Argument.

Returns:

the norm.

of

public final double of(double x,
 double y,
 double z)

Computes the norm.

Special cases:

• If any value is Double.NaN, then the result is Double.NaN.
• If any value is infinite and no value is not Double.NaN, then the result is Double.POSITIVE_INFINITY.

Parameters:

x - Argument.

y - Argument.

z - Argument.

Returns:

the norm.

of

public final double of(double[] v)

Computes the norm.

Special cases:

• If any value is Double.NaN, then the result is Double.NaN.
• If any value is infinite and no value is not Double.NaN, then the result is Double.POSITIVE_INFINITY.

Parameters:

v - Argument.

Returns:

the norm.

Throws:

IllegalArgumentException - if the array is empty.