fr.cnes.sirius.patrius.math

Class Comparators

java.lang.Object

fr.cnes.sirius.patrius.math.Comparators

public final class Comparators
extends Object

- Static comparison methods for real numbers

- Classical methods to compare doubles using an epsilon, as an input or with a default value

See DV-MATHS_30.

Since:

1.0

Version:

$Id: Comparators.java 17584 2017-05-10 13:26:39Z bignon $

Author:

Thomas TRAPIER

Use sample :

Those methods can be used this way : if (greaterOrEqual(x, y)) {...}

The condition is "true" if x is greater or equal to y (with a relative comparison using the default epsilon)

Concurrency :

unconditionally thread-safe

Field Summary

Fields

Modifier and Type	Field and Description
static double	DOUBLE_COMPARISON_EPSILON The epsilon used for doubles relative comparison

Method Summary

Modifier and Type	Method and Description
static boolean	equals(double x, double y) Tests the equality between doubles with a relative comparison using a default epsilon.
static boolean	equals(double x, double y, double eps) Tests the equality between doubles with a relative comparison using an input epsilon.
static boolean	equalsWithRelativeTolerance(double x, double y, double eps) Copied from commons math Precision.equalsWithRelativeTolerance(double, double, double).
static boolean	greaterOrEqual(double x, double y) Tests if a double is greater or equal to another with a relative comparison using a default epsilon.
static boolean	greaterOrEqual(double x, double y, double eps) Tests if a double is greater or equal to another with a relative comparison using an input epsilon.
static boolean	greaterStrict(double x, double y) Tests if a double is strictly greater than another with a relative comparison using a default epsilon.
static boolean	greaterStrict(double x, double y, double eps) Tests if a double is strictly greater than another with a relative comparison using an input epsilon.
static boolean	lowerOrEqual(double x, double y) Tests if a double is lower or equal to another with a relative comparison using a default epsilon.
static boolean	lowerOrEqual(double x, double y, double eps) Tests if a double is lower or equal to another with a relative comparison using an input epsilon.
static boolean	lowerStrict(double x, double y) Tests if a double is strictly lower than another with a relative comparison using a default epsilon.
static boolean	lowerStrict(double x, double y, double eps) Tests if a double is strictly lower than another with a relative comparison using an input epsilon.

Methods inherited from class java.lang.Object

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

Field Detail

DOUBLE_COMPARISON_EPSILON

public static final double DOUBLE_COMPARISON_EPSILON

The epsilon used for doubles relative comparison

See Also:

Constant Field Values

Method Detail

equals

public static boolean equals(double x,
                             double y)

Tests the equality between doubles with a relative comparison using a default epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

Returns:

a boolean : "true" if the doubles are found equals.

The value "Nan" as input always imply the return "false"

Since:

1.0

equals

public static boolean equals(double x,
                             double y,
                             double eps)

Tests the equality between doubles with a relative comparison using an input epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

eps - epsilon used in the relative comparison

Returns:

a boolean : "true" if the doubles are found equals.

The value "Nan" as input always imply the return "false"

Since:

1.0

lowerOrEqual

public static boolean lowerOrEqual(double x,
                                   double y)

Tests if a double is lower or equal to another with a relative comparison using a default epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

Returns:

a boolean : "true" if x is found lower or equal to y.

The value "Nan" as input always imply the return "false"

Since:

1.0

lowerOrEqual

public static boolean lowerOrEqual(double x,
                                   double y,
                                   double eps)

Tests if a double is lower or equal to another with a relative comparison using an input epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

eps - epsilon used in the relative comparison

Returns:

a boolean : "true" if x is found lower or equal to y.

The value "Nan" as input always imply the return "false"

Since:

1.0

greaterOrEqual

public static boolean greaterOrEqual(double x,
                                     double y)

Tests if a double is greater or equal to another with a relative comparison using a default epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

Returns:

a boolean : "true" if x is found greater or equal to y.

The value "Nan" as input always imply the return "false"

Since:

1.0

greaterOrEqual

public static boolean greaterOrEqual(double x,
                                     double y,
                                     double eps)

Tests if a double is greater or equal to another with a relative comparison using an input epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

eps - epsilon used in the relative comparison

Returns:

a boolean : "true" if x is found greater or equal to y.

The value "Nan" as input always imply the return "false"

Since:

1.0

lowerStrict

public static boolean lowerStrict(double x,
                                  double y)

Tests if a double is strictly lower than another with a relative comparison using a default epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

Returns:

a boolean : "true" if x is found lower than y.

The value "Nan" as input always imply the return "false"

Since:

1.0

lowerStrict

public static boolean lowerStrict(double x,
                                  double y,
                                  double eps)

Tests if a double is strictly lower than another with a relative comparison using an input epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

eps - epsilon used in the relative comparison

Returns:

a boolean : "true" if x is found lower than y.

The value "Nan" as input always imply the return "false"

Since:

1.0

equalsWithRelativeTolerance

public static boolean equalsWithRelativeTolerance(double x,
                                                  double y,
                                                  double eps)

Copied from commons math Precision.equalsWithRelativeTolerance(double, double, double). Returns true if the difference between the number is smaller or equal to the given tolerance. The difference is the call to the Precision.equals(double, double, int). The ulp is 0 instead of 1. This means that two adjacent numbers are not considered equal.

Parameters:

x - First value.

y - Second value.

eps - Amount of allowed relative error.

Returns:

true if the values are two adjacent floating point numbers or they are within range of each other.

Since:

2.1

greaterStrict

public static boolean greaterStrict(double x,
                                    double y)

Tests if a double is strictly greater than another with a relative comparison using a default epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

Returns:

a boolean : "true" if x is found greater than y.

The value "Nan" as input always imply the return "false"

Since:

1.0

greaterStrict

public static boolean greaterStrict(double x,
                                    double y,
                                    double eps)

Tests if a double is strictly greater than another with a relative comparison using an input epsilon.

Parameters:

x - first double to be compared

y - second double to be compared

eps - epsilon used in the relative comparison

Returns:

a boolean : "true" if x is found greater than y.

The value "Nan" as input always imply the return "false"

Since:

1.0