Package ucar.nc2.util

Class Misc

java.lang.Object

ucar.nc2.util.Misc

public class Misc
extends Object

Miscellaneous static routines.

Field Summary

Fields

Modifier and Type	Field	Description
static double	defaultDiffFLoat	The default maximum relative difference for floats, when comparing as doubles.
static double	defaultMaxRelativeDiffDouble	The default maximum relative difference that two doubles can have in order to be deemed nearly equal.
static float	defaultMaxRelativeDiffFloat	The default maximum relative difference that two floats can have in order to be deemed nearly equal.
static int	objectSize	Estimates object size in bytes
static int	referenceSize	Estimates pointer size in bytes

Constructor Summary

Constructors

Constructor	Description
Misc()

Method Summary

Modifier and Type	Method	Description
static double	absoluteDifference(double a, double b)	The absolute difference between two doubles, i.e.
static float	absoluteDifference(float a, float b)	The absolute difference between two floats, i.e.
static boolean	compare(byte[] raw1, byte[] raw2, Formatter f)	For testing, use Truth.assertThat(raw1).isEqualTo(raw2)
static boolean	compare(float[] raw1, float[] raw2, Formatter f)	For testing, use Truth.assertThat(raw1).isEqualTo(raw2)
static boolean	compare(int[] raw1, int[] raw2, Formatter f)	For testing, use Truth.assertThat(raw1).isEqualTo(raw2)
static boolean	nearlyEquals(double a, double b)	RelativeDifference is less than defaultMaxRelativeDiffDouble.
static boolean	nearlyEquals(double a, double b, double maxRelDiff)	RelativeDifference is less than maxRelDiff.
static boolean	nearlyEquals(float a, float b)	RelativeDifference is less than defaultMaxRelativeDiffFloat.
static boolean	nearlyEquals(float a, float b, float maxRelDiff)	RelativeDifference is less than maxRelDiff.
static boolean	nearlyEqualsAbs(double a, double b, double maxAbsDiff)	AbsoluteDifference is less than maxAbsDiff.
static boolean	nearlyEqualsAbs(float a, float b, float maxAbsDiff)	AbsoluteDifference is less than maxAbsDiff.
static double	relativeDifference(double a, double b)	Same as relativeDifference(float, float), but for doubles.
static float	relativeDifference(float a, float b)	Returns the relative difference between two numbers, i.e.
static String	showBits(byte[] bytes)
static void	showClassPath()

Methods inherited from class java.lang.Object

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

Field Detail

referenceSize

public static final int referenceSize

Estimates pointer size in bytes

See Also:

Constant Field Values

objectSize

public static final int objectSize

Estimates object size in bytes

See Also:

Constant Field Values

defaultMaxRelativeDiffFloat

public static final float defaultMaxRelativeDiffFloat

The default maximum relative difference that two floats can have in order to be deemed nearly equal.

See Also:

Constant Field Values

defaultDiffFLoat

public static final double defaultDiffFLoat

The default maximum relative difference for floats, when comparing as doubles.

See Also:

Constant Field Values

defaultMaxRelativeDiffDouble

public static final double defaultMaxRelativeDiffDouble

The default maximum relative difference that two doubles can have in order to be deemed nearly equal.

See Also:

Constant Field Values

Constructor Detail

Misc

public Misc()

Method Detail

absoluteDifference

public static float absoluteDifference(float a,
                                       float b)

The absolute difference between two floats, i.e. |a - b|.

absoluteDifference

public static double absoluteDifference(double a,
                                        double b)

The absolute difference between two doubles, i.e. |a - b|.

relativeDifference

public static float relativeDifference(float a,
                                       float b)

Returns the relative difference between two numbers, i.e. |a - b| / max(|a|, |b|).

For cases where a == 0, b == 0, or a and b are extremely close, traditional relative difference calculation breaks down. So, in those instances, we compute the difference relative to Float.MIN_NORMAL, i.e. |a - b| / Float.MIN_NORMAL.

Parameters:

a - first number.

b - second number.

Returns:

the relative difference.

See Also:

The Floating-Point Guide, Comparing Floating Point Numbers, 2012 Edition

relativeDifference

public static double relativeDifference(double a,
                                        double b)

Same as relativeDifference(float, float), but for doubles.

nearlyEquals

public static boolean nearlyEquals(float a,
                                   float b)

RelativeDifference is less than defaultMaxRelativeDiffFloat.

nearlyEquals

public static boolean nearlyEquals(float a,
                                   float b,
                                   float maxRelDiff)

RelativeDifference is less than maxRelDiff.

nearlyEquals

public static boolean nearlyEquals(double a,
                                   double b)

RelativeDifference is less than defaultMaxRelativeDiffDouble.

nearlyEquals

public static boolean nearlyEquals(double a,
                                   double b,
                                   double maxRelDiff)

RelativeDifference is less than maxRelDiff.

nearlyEqualsAbs

public static boolean nearlyEqualsAbs(float a,
                                      float b,
                                      float maxAbsDiff)

AbsoluteDifference is less than maxAbsDiff.

nearlyEqualsAbs

public static boolean nearlyEqualsAbs(double a,
                                      double b,
                                      double maxAbsDiff)

AbsoluteDifference is less than maxAbsDiff.

showBits

public static String showBits(byte[] bytes)

compare

public static boolean compare(byte[] raw1,
                              byte[] raw2,
                              Formatter f)

For testing, use Truth.assertThat(raw1).isEqualTo(raw2)

compare

public static boolean compare(float[] raw1,
                              float[] raw2,
                              Formatter f)

For testing, use Truth.assertThat(raw1).isEqualTo(raw2)

compare

public static boolean compare(int[] raw1,
                              int[] raw2,
                              Formatter f)

For testing, use Truth.assertThat(raw1).isEqualTo(raw2)

showClassPath

public static void showClassPath()