## org.jfree.chart.axis
Class LogAxis

    java.lang.Object
      org.jfree.chart.axis.Axis
          org.jfree.chart.axis.ValueAxis
              org.jfree.chart.axis.LogAxis

All Implemented Interfaces:
  java.io.Serializable, java.lang.Cloneable, org.jfree.util.PublicCloneable

    public class LogAxis

extends ValueAxis

A numerical axis that uses a logarithmic scale. The class is an alternative to the `LogarithmicAxis` class.

Since:
  1.0.7
See Also:
  Serialized Form

Field Summary

Fields inherited from class org.jfree.chart.axis.ValueAxis
`DEFAULT_AUTO_RANGE, DEFAULT_AUTO_RANGE_MINIMUM_SIZE, DEFAULT_AUTO_TICK_UNIT_SELECTION, DEFAULT_INVERTED, DEFAULT_LOWER_BOUND, DEFAULT_LOWER_MARGIN, DEFAULT_RANGE, DEFAULT_UPPER_BOUND, DEFAULT_UPPER_MARGIN, MAXIMUM_TICK_COUNT`

Fields inherited from class org.jfree.chart.axis.Axis

`DEFAULT_AXIS_LABEL_FONT, DEFAULT_AXIS_LABEL_INSETS, DEFAULT_AXIS_LABEL_PAINT, DEFAULT_AXIS_LINE_PAINT, DEFAULT_AXIS_LINE_STROKE, DEFAULT_AXIS_VISIBLE, DEFAULT_TICK_LABEL_FONT, DEFAULT_TICK_LABEL_INSETS, DEFAULT_TICK_LABEL_PAINT, DEFAULT_TICK_LABELS_VISIBLE, DEFAULT_TICK_MARK_INSIDE_LENGTH, DEFAULT_TICK_MARK_OUTSIDE_LENGTH, DEFAULT_TICK_MARK_PAINT, DEFAULT_TICK_MARK_STROKE, DEFAULT_TICK_MARKS_VISIBLE`

Constructor Summary
`LogAxis()` Creates a new `LogAxis` with no label.
`LogAxis(java.lang.String label)` Creates a new `LogAxis` with the given label.

Method Summary
`protected void` `autoAdjustRange()` Adjusts the axis range to match the data range that the axis is required to display.
`double` `calculateLog(double value)` Calculates the log of the given value, using the current base.
`double` `calculateValue(double log)` Calculates the value from a given log.
`void` `configure()` Configures the axis.
`static TickUnitSource` `createLogTickUnits(java.util.Locale locale)` Returns a collection of tick units for log (base 10) values.
`protected java.lang.String` `createTickLabel(double value)` Creates a tick label for the specified value.
`AxisState` `draw(java.awt.Graphics2D g2, double cursor, java.awt.geom.Rectangle2D plotArea, java.awt.geom.Rectangle2D dataArea, org.jfree.ui.RectangleEdge edge, PlotRenderingInfo plotState)` Draws the axis on a Java 2D graphics device (such as the screen or a printer).
`boolean` `equals(java.lang.Object obj)` Tests this axis for equality with an arbitrary object.
`protected double` `estimateMaximumTickLabelHeight(java.awt.Graphics2D g2)` Estimates the maximum tick label height.
`protected double` `estimateMaximumTickLabelWidth(java.awt.Graphics2D g2, TickUnit unit)` Estimates the maximum width of the tick labels, assuming the specified tick unit is used.
`double` `exponentLengthToJava2D(double length, java.awt.geom.Rectangle2D area, org.jfree.ui.RectangleEdge edge)` Converts a length in data coordinates into the corresponding length in Java2D coordinates.
`double` `getBase()` Returns the base for the logarithm calculation.
`int` `getMinorTickCount()` Returns the number of minor tick marks to display.
`java.text.NumberFormat` `getNumberFormatOverride()` Returns the number format override.
`double` `getSmallestValue()` Returns the smallest value represented by the axis.
`NumberTickUnit` `getTickUnit()` Returns the current tick unit.
`int` `hashCode()` Returns a hash code for this instance.
`double` `java2DToValue(double java2DValue, java.awt.geom.Rectangle2D area, org.jfree.ui.RectangleEdge edge)` Converts a Java2D coordinate to an axis value, assuming that the axis covers the specified `edge` of the `area`.
`java.util.List` `refreshTicks(java.awt.Graphics2D g2, AxisState state, java.awt.geom.Rectangle2D dataArea, org.jfree.ui.RectangleEdge edge)` Calculates the positions of the tick labels for the axis, storing the results in the tick label list (ready for drawing).
`protected java.util.List` `refreshTicksHorizontal(java.awt.Graphics2D g2, java.awt.geom.Rectangle2D dataArea, org.jfree.ui.RectangleEdge edge)` Returns a list of ticks for an axis at the top or bottom of the chart.
`protected java.util.List` `refreshTicksVertical(java.awt.Graphics2D g2, java.awt.geom.Rectangle2D dataArea, org.jfree.ui.RectangleEdge edge)` Returns a list of ticks for an axis at the left or right of the chart.
`protected void` `selectAutoTickUnit(java.awt.Graphics2D g2, java.awt.geom.Rectangle2D dataArea, org.jfree.ui.RectangleEdge edge)` Selects an appropriate tick value for the axis.
`protected void` `selectHorizontalAutoTickUnit(java.awt.Graphics2D g2, java.awt.geom.Rectangle2D dataArea, org.jfree.ui.RectangleEdge edge)` Selects an appropriate tick value for the axis.
`protected void` `selectVerticalAutoTickUnit(java.awt.Graphics2D g2, java.awt.geom.Rectangle2D dataArea, org.jfree.ui.RectangleEdge edge)` Selects an appropriate tick value for the axis.
`void` `setBase(double base)` Sets the base for the logarithm calculation and sends an `AxisChangeEvent` to all registered listeners.
`void` `setMinorTickCount(int count)` Sets the number of minor tick marks to display, and sends an `AxisChangeEvent` to all registered listeners.
`void` `setNumberFormatOverride(java.text.NumberFormat formatter)` Sets the number format override.
`void` `setSmallestValue(double value)` Sets the smallest value represented by the axis and sends an `AxisChangeEvent` to all registered listeners.
`void` `setTickUnit(NumberTickUnit unit)` Sets the tick unit for the axis and sends an `AxisChangeEvent` to all registered listeners.
`void` `setTickUnit(NumberTickUnit unit, boolean notify, boolean turnOffAutoSelect)` Sets the tick unit for the axis and, if requested, sends an `AxisChangeEvent` to all registered listeners.
`double` `valueToJava2D(double value, java.awt.geom.Rectangle2D area, org.jfree.ui.RectangleEdge edge)` Converts a value on the axis scale to a Java2D coordinate relative to the given `area`, based on the axis running along the specified `edge`.
`void` `zoomRange(double lowerPercent, double upperPercent)` Zooms in on the current range.

Methods inherited from class org.jfree.chart.axis.ValueAxis

`calculateAnchorPoint, centerRange, clone, drawAxisLine, drawTickMarksAndLabels, findMaximumTickLabelHeight, findMaximumTickLabelWidth, getAutoRangeMinimumSize, getAutoTickIndex, getDefaultAutoRange, getDownArrow, getFixedAutoRange, getLeftArrow, getLowerBound, getLowerMargin, getRange, getRightArrow, getStandardTickUnits, getUpArrow, getUpperBound, getUpperMargin, isAutoRange, isAutoTickUnitSelection, isInverted, isNegativeArrowVisible, isPositiveArrowVisible, isVerticalTickLabels, lengthToJava2D, reserveSpace, resizeRange, resizeRange, setAutoRange, setAutoRange, setAutoRangeMinimumSize, setAutoRangeMinimumSize, setAutoTickIndex, setAutoTickUnitSelection, setAutoTickUnitSelection, setDefaultAutoRange, setDownArrow, setFixedAutoRange, setInverted, setLeftArrow, setLowerBound, setLowerMargin, setNegativeArrowVisible, setPositiveArrowVisible, setRange, setRange, setRange, setRangeAboutValue, setRangeWithMargins, setRangeWithMargins, setRangeWithMargins, setRightArrow, setStandardTickUnits, setUpArrow, setUpperBound, setUpperMargin, setVerticalTickLabels`

Methods inherited from class org.jfree.chart.axis.Axis

`addChangeListener, drawLabel, getAxisLinePaint, getAxisLineStroke, getFixedDimension, getLabel, getLabelAngle, getLabelEnclosure, getLabelFont, getLabelInsets, getLabelPaint, getPlot, getTickLabelFont, getTickLabelInsets, getTickLabelPaint, getTickMarkInsideLength, getTickMarkOutsideLength, getTickMarkPaint, getTickMarkStroke, hasListener, isAxisLineVisible, isTickLabelsVisible, isTickMarksVisible, isVisible, notifyListeners, removeChangeListener, setAxisLinePaint, setAxisLineStroke, setAxisLineVisible, setFixedDimension, setLabel, setLabelAngle, setLabelFont, setLabelInsets, setLabelInsets, setLabelPaint, setPlot, setTickLabelFont, setTickLabelInsets, setTickLabelPaint, setTickLabelsVisible, setTickMarkInsideLength, setTickMarkOutsideLength, setTickMarkPaint, setTickMarkStroke, setTickMarksVisible, setVisible`

Methods inherited from class java.lang.Object
`finalize, getClass, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### LogAxis

    public LogAxis()

  Creates a new `LogAxis` with no label.

### LogAxis

    public LogAxis(java.lang.String label)

  Creates a new `LogAxis` with the given label.

  Parameters:
    `label` - the axis label (`null` permitted).

Method Detail

### getBase

    public double getBase()

  Returns the base for the logarithm calculation.

  Returns:
    The base for the logarithm calculation.
  See Also:
    `setBase(double)`

### setBase

    public void setBase(double base)

  Sets the base for the logarithm calculation and sends an `AxisChangeEvent` to all registered listeners.

  Parameters:
    `base` - the base value (must be > 1.0).
  See Also:
    `getBase()`

### getSmallestValue

    public double getSmallestValue()

  Returns the smallest value represented by the axis.

  Returns:
    The smallest value represented by the axis.
  See Also:
    `setSmallestValue(double)`

### setSmallestValue

    public void setSmallestValue(double value)

  Sets the smallest value represented by the axis and sends an `AxisChangeEvent` to all registered listeners.

  Parameters:
    `value` - the value.
  See Also:
    `getSmallestValue()`

### getTickUnit

    public NumberTickUnit getTickUnit()

  Returns the current tick unit.

  Returns:
    The current tick unit.
  See Also:
    `setTickUnit(NumberTickUnit)`

### setTickUnit

    public void setTickUnit(NumberTickUnit unit)

  Sets the tick unit for the axis and sends an `AxisChangeEvent` to all registered listeners. A side effect of calling this method is that the "auto-select" feature for tick units is switched off (you can restore it using the `ValueAxis.setAutoTickUnitSelection(boolean)` method).

  Parameters:
    `unit` - the new tick unit (`null` not permitted).
  See Also:
    `getTickUnit()`

### setTickUnit

    public void setTickUnit(NumberTickUnit unit,
                            boolean notify,
                            boolean turnOffAutoSelect)

  Sets the tick unit for the axis and, if requested, sends an `AxisChangeEvent` to all registered listeners. In addition, an option is provided to turn off the "auto-select" feature for tick units (you can restore it using the `ValueAxis.setAutoTickUnitSelection(boolean)` method).

  Parameters:
    `unit` - the new tick unit (`null` not permitted).
    `notify` - notify listeners?
    `turnOffAutoSelect` - turn off the auto-tick selection?
  See Also:
    `getTickUnit()`

### getNumberFormatOverride

    public java.text.NumberFormat getNumberFormatOverride()

  Returns the number format override. If this is non-null, then it will be used to format the numbers on the axis.

  Returns:
    The number formatter (possibly `null`).
  See Also:
    `setNumberFormatOverride(NumberFormat)`

### setNumberFormatOverride

    public void setNumberFormatOverride(java.text.NumberFormat formatter)

  Sets the number format override. If this is non-null, then it will be used to format the numbers on the axis.

  Parameters:
    `formatter` - the number formatter (`null` permitted).
  See Also:
    `getNumberFormatOverride()`

### getMinorTickCount

    public int getMinorTickCount()

  Returns the number of minor tick marks to display.

  Returns:
    The number of minor tick marks to display.
  See Also:
    `setMinorTickCount(int)`

### setMinorTickCount

    public void setMinorTickCount(int count)

  Sets the number of minor tick marks to display, and sends an `AxisChangeEvent` to all registered listeners.

  Parameters:
    `count` - the count.
  See Also:
    `getMinorTickCount()`

### calculateLog

    public double calculateLog(double value)

  Calculates the log of the given value, using the current base.

  Parameters:
    `value` - the value.
  Returns:
    The log of the given value.
  See Also:
    `calculateValue(double)`, `getBase()`

### calculateValue

    public double calculateValue(double log)

  Calculates the value from a given log.

  Parameters:
    `log` - the log value (must be > 0.0).
  Returns:
    The value with the given log.
  See Also:
    `calculateLog(double)`, `getBase()`

### java2DToValue

    public double java2DToValue(double java2DValue,
                                java.awt.geom.Rectangle2D area,
                                org.jfree.ui.RectangleEdge edge)

  Converts a Java2D coordinate to an axis value, assuming that the axis covers the specified `edge` of the `area`.

  Specified by:
    `java2DToValue` in class `ValueAxis`
  Parameters:
    `java2DValue` - the Java2D coordinate.
    `area` - the area.
    `edge` - the edge that the axis belongs to.
  Returns:
    A value along the axis scale.
  See Also:
    `ValueAxis.valueToJava2D(double, Rectangle2D, RectangleEdge)`

### valueToJava2D

    public double valueToJava2D(double value,
                                java.awt.geom.Rectangle2D area,
                                org.jfree.ui.RectangleEdge edge)

  Converts a value on the axis scale to a Java2D coordinate relative to the given `area`, based on the axis running along the specified `edge`.

  Specified by:
    `valueToJava2D` in class `ValueAxis`
  Parameters:
    `value` - the data value.
    `area` - the area.
    `edge` - the edge.
  Returns:
    The Java2D coordinate corresponding to `value`.
  See Also:
    `ValueAxis.java2DToValue(double, Rectangle2D, RectangleEdge)`

### configure

    public void configure()

  Configures the axis. This method is typically called when an axis is assigned to a new plot.

  Specified by:
    `configure` in class `Axis`

### autoAdjustRange

    protected void autoAdjustRange()

  Adjusts the axis range to match the data range that the axis is required to display.

  Specified by:
    `autoAdjustRange` in class `ValueAxis`

### draw

    public AxisState draw(java.awt.Graphics2D g2,
                          double cursor,
                          java.awt.geom.Rectangle2D plotArea,
                          java.awt.geom.Rectangle2D dataArea,
                          org.jfree.ui.RectangleEdge edge,
                          PlotRenderingInfo plotState)

  Draws the axis on a Java 2D graphics device (such as the screen or a printer).

  Specified by:
    `draw` in class `Axis`
  Parameters:
    `g2` - the graphics device (`null` not permitted).
    `cursor` - the cursor location (determines where to draw the axis).
    `plotArea` - the area within which the axes and plot should be drawn.
    `dataArea` - the area within which the data should be drawn.
    `edge` - the axis location (`null` not permitted).
    `plotState` - collects information about the plot (`null` permitted).
  Returns:
    The axis state (never `null`).

### refreshTicks

    public java.util.List refreshTicks(java.awt.Graphics2D g2,
                                       AxisState state,
                                       java.awt.geom.Rectangle2D dataArea,
                                       org.jfree.ui.RectangleEdge edge)

  Calculates the positions of the tick labels for the axis, storing the results in the tick label list (ready for drawing).

  Specified by:
    `refreshTicks` in class `Axis`
  Parameters:
    `g2` - the graphics device.
    `state` - the axis state.
    `dataArea` - the area in which the plot should be drawn.
    `edge` - the location of the axis.
  Returns:
    A list of ticks.

### refreshTicksHorizontal

    protected java.util.List refreshTicksHorizontal(java.awt.Graphics2D g2,
                                                    java.awt.geom.Rectangle2D dataArea,
                                                    org.jfree.ui.RectangleEdge edge)

  Returns a list of ticks for an axis at the top or bottom of the chart.

  Parameters:
    `g2` - the graphics device.
    `dataArea` - the data area.
    `edge` - the edge.
  Returns:
    A list of ticks.

### refreshTicksVertical

    protected java.util.List refreshTicksVertical(java.awt.Graphics2D g2,
                                                  java.awt.geom.Rectangle2D dataArea,
                                                  org.jfree.ui.RectangleEdge edge)

  Returns a list of ticks for an axis at the left or right of the chart.

  Parameters:
    `g2` - the graphics device.
    `dataArea` - the data area.
    `edge` - the edge.
  Returns:
    A list of ticks.

### selectAutoTickUnit

    protected void selectAutoTickUnit(java.awt.Graphics2D g2,
                                      java.awt.geom.Rectangle2D dataArea,
                                      org.jfree.ui.RectangleEdge edge)

  Selects an appropriate tick value for the axis. The strategy is to display as many ticks as possible (selected from an array of 'standard' tick units) without the labels overlapping.

  Parameters:
    `g2` - the graphics device.
    `dataArea` - the area defined by the axes.
    `edge` - the axis location.
  Since:
    1.0.7

### selectHorizontalAutoTickUnit

    protected void selectHorizontalAutoTickUnit(java.awt.Graphics2D g2,
                                                java.awt.geom.Rectangle2D dataArea,
                                                org.jfree.ui.RectangleEdge edge)

  Selects an appropriate tick value for the axis. The strategy is to display as many ticks as possible (selected from an array of 'standard' tick units) without the labels overlapping.

  Parameters:
    `g2` - the graphics device.
    `dataArea` - the area defined by the axes.
    `edge` - the axis location.
  Since:
    1.0.7

### exponentLengthToJava2D

    public double exponentLengthToJava2D(double length,
                                         java.awt.geom.Rectangle2D area,
                                         org.jfree.ui.RectangleEdge edge)

  Converts a length in data coordinates into the corresponding length in Java2D coordinates.

  Parameters:
    `length` - the length.
    `area` - the plot area.
    `edge` - the edge along which the axis lies.
  Returns:
    The length in Java2D coordinates.
  Since:
    1.0.7

### selectVerticalAutoTickUnit

    protected void selectVerticalAutoTickUnit(java.awt.Graphics2D g2,
                                              java.awt.geom.Rectangle2D dataArea,
                                              org.jfree.ui.RectangleEdge edge)

  Selects an appropriate tick value for the axis. The strategy is to display as many ticks as possible (selected from an array of 'standard' tick units) without the labels overlapping.

  Parameters:
    `g2` - the graphics device.
    `dataArea` - the area in which the plot should be drawn.
    `edge` - the axis location.
  Since:
    1.0.7

### estimateMaximumTickLabelHeight

    protected double estimateMaximumTickLabelHeight(java.awt.Graphics2D g2)

  Estimates the maximum tick label height.

  Parameters:
    `g2` - the graphics device.
  Returns:
    The maximum height.
  Since:
    1.0.7

### estimateMaximumTickLabelWidth

    protected double estimateMaximumTickLabelWidth(java.awt.Graphics2D g2,
                                                   TickUnit unit)

  Estimates the maximum width of the tick labels, assuming the specified tick unit is used.

  Rather than computing the string bounds of every tick on the axis, we just look at two values: the lower bound and the upper bound for the axis. These two values will usually be representative.

  Parameters:
    `g2` - the graphics device.
    `unit` - the tick unit to use for calculation.
  Returns:
    The estimated maximum width of the tick labels.
  Since:
    1.0.7

### zoomRange

    public void zoomRange(double lowerPercent,
                          double upperPercent)

  Zooms in on the current range.

  Overrides:
    `zoomRange` in class `ValueAxis`
  Parameters:
    `lowerPercent` - the new lower bound.
    `upperPercent` - the new upper bound.

### createTickLabel

    protected java.lang.String createTickLabel(double value)

  Creates a tick label for the specified value. Note that this method was 'private' prior to version 1.0.10.

  Parameters:
    `value` - the value.
  Returns:
    The label.
  Since:
    1.0.10

### equals

    public boolean equals(java.lang.Object obj)

  Tests this axis for equality with an arbitrary object.

  Overrides:
    `equals` in class `ValueAxis`
  Parameters:
    `obj` - the object (`null` permitted).
  Returns:
    A boolean.

### hashCode

    public int hashCode()

  Returns a hash code for this instance.

  Overrides:
    `hashCode` in class `java.lang.Object`
  Returns:
    A hash code.

### createLogTickUnits

    public static TickUnitSource createLogTickUnits(java.util.Locale locale)

  Returns a collection of tick units for log (base 10) values. Uses a given Locale to create the DecimalFormats.

  Parameters:
    `locale` - the locale to use to represent Numbers.
  Returns:
    A collection of tick units for integer values.
  Since:
    1.0.7