org.eclipse.nebula.visualization.xygraph.util

Class Log10

java.lang.Object

org.eclipse.nebula.visualization.xygraph.util.Log10

public class Log10
extends java.lang.Object

Helper for log10-related computations.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static double	HUGE_NEGATIVE

Constructor Summary

Constructors

Constructor and Description
Log10()

Method Summary

Modifier and Type	Method and Description
static double	log10(double val) Adjusted log10 to handle values less or equal to zero.
static double	pow10(double value)

Methods inherited from class java.lang.Object

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

Field Detail

HUGE_NEGATIVE

static final double HUGE_NEGATIVE

See Also:

Constant Field Values

Constructor Detail

Log10

public Log10()

Method Detail

log10

public static double log10(double val)

Adjusted log10 to handle values less or equal to zero.

The logarithm does not result in real numbers for arguments less or equal to zero, but the plot should still somehow handle such values without crashing. So anything ≤ 0 is mapped to a 'really big negative' number just for the sake of plotting.

Note that LogarithmicAxis.java in the JFreeChart has another interesting idea for modifying the log10 of values ≤ 10, resulting in a smooth plot for the full real argument range. Unfortunately that clobbers values like 1e-7, which might be a very real vacuum reading.

Parameters:

val - value for which log₁₀ should be calculated.

Returns:

an adjusted log₁₀(val).

pow10

public static double pow10(double value)

Returns:

pow(10, value)