jaitools.numeric
Class DoubleComparison

java.lang.Object
  jaitools.numeric.DoubleComparison

public class DoubleComparison
extends Object

Provides static method to compare double values with either a default or specified tolerance.

Since:

1.0

Version:

$Id: DoubleComparison.java 1504 2011-03-05 10:56:10Z michael.bedward $

Author:

Michael Bedward

Field Summary

static double

TOL Default tolerance for comparisons: 1.0e-8

Constructor Summary

DoubleComparison()

Method Summary

static int	dcomp(double x1, double x2) Compares two values using the default tolerance.
static int	dcomp(double x1, double x2, double tol) Compares two values using the user-specified tolerance
static boolean	dequal(double x1, double x2) Tests if two double values are equal within the default tolerance.
static boolean	dequal(double x1, double x2, double tol) Tests if two double values are equal within the specified tolerance.
static boolean	dzero(double x) Tests if the given value is 0 within the default tolerance.
static boolean	dzero(double x, double tol) Tests if the given value is 0 within the user-specified tolerance.
static int	toInt(double x) Converts a double value to integer taking into account the default tolerance when checking if it is zero, ie.

Methods inherited from class java.lang.Object

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

Field Detail

TOL

public static final double TOL

Default tolerance for comparisons: 1.0e-8

See Also:

Constant Field Values

Constructor Detail

DoubleComparison

public DoubleComparison()

Method Detail

dzero

public static boolean dzero(double x)

Tests if the given value is 0 within the default tolerance.

Parameters:

x - the value

Returns:

true if zero; false otherwise

dzero

public static boolean dzero(double x,
                            double tol)

Tests if the given value is 0 within the user-specified tolerance.

Parameters:

x - the value

tol - the user-specified tolerance (assumed to be positive)

Returns:

true if zero; false otherwise

dcomp

public static int dcomp(double x1,
                        double x2)

Compares two values using the default tolerance.

Parameters:

x1 - first value

x2 - second value

Returns:

a value less than 0 if x1 is less than x2; 0 if x1 is equal to x2; a value greater than 0 if x1 is greater than x2

dcomp

public static int dcomp(double x1,
                        double x2,
                        double tol)

Compares two values using the user-specified tolerance

Parameters:

x1 - first value

x2 - second value

tol - the tolerance

Returns:

a value less than 0 if x1 is less than x2; 0 if x1 is equal to x2; a value greater than 0 if x1 is greater than x2

dequal

public static boolean dequal(double x1,
                             double x2)

Tests if two double values are equal within the default tolerance. This is a short-cut for dzero(x1 - x2).

Parameters:

x1 - first value

x2 - second value

Returns:

true if equal; false otherwise

dequal

public static boolean dequal(double x1,
                             double x2,
                             double tol)

Tests if two double values are equal within the specified tolerance. This is a short-cut for dzero(x1 - x2, tol).

Parameters:

x1 - first value

x2 - second value

tol - the tolerance

Returns:

true if equal; false otherwise

toInt

public static int toInt(double x)

Converts a double value to integer taking into account the default tolerance when checking if it is zero, ie. values within TOL either side of 0 will produce a 0 return value

Parameters:

x - the value to convert

Returns:

the equivalent integer value