org.lenskit.util.math

Class Scalars

java.lang.Object

org.lenskit.util.math.Scalars

public final class Scalars
extends java.lang.Object

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_EPSILON The default epsilon for checking for zero.

Method Summary

Modifier and Type	Method and Description
static boolean	isZero(double val) Check whether a value is zero, using a default epsilon.
static boolean	isZero(double val, double epsilon) Check whether a value is zero, using a configurable epsilon.
static double	log2(double x)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_EPSILON

public static final double DEFAULT_EPSILON

The default epsilon for checking for zero. If the Java system property lenskit.zero.epsilon is set, the value of that is used; otherwise, Double.MIN_NORMAL.

Method Detail

isZero

public static boolean isZero(double val)

Check whether a value is zero, using a default epsilon.

Parameters:

val - The value.

Returns:

true if the value is within an epsilon of zero.

isZero

public static boolean isZero(double val,
                             double epsilon)

Check whether a value is zero, using a configurable epsilon.

Parameters:

val - The value.

epsilon - The tolerance.

Returns:

true if absolute value of val is less than epsilon.

log2

public static double log2(double x)