public class

NumberAxis

extends ValueAxis
implements Serializable Cloneable
java.lang.Object
   ↳ org.jfree.chart.axis.Axis
     ↳ org.jfree.chart.axis.ValueAxis
       ↳ org.jfree.chart.axis.NumberAxis
Known Direct Subclasses

Class Overview

An axis for displaying numerical data.

If the axis is set up to automatically determine its range to fit the data, you can ensure that the range includes zero (statisticians usually prefer this) by setting the autoRangeIncludesZero flag to true.

The NumberAxis class has a mechanism for automatically selecting a tick unit that is appropriate for the current axis range. This mechanism is an adaptation of code suggested by Laurence Vanhelsuwe.

Summary

Constants
boolean DEFAULT_AUTO_RANGE_INCLUDES_ZERO The default value for the autoRangeIncludesZero flag.
boolean DEFAULT_AUTO_RANGE_STICKY_ZERO The default value for the autoRangeStickyZero flag.
boolean DEFAULT_VERTICAL_TICK_LABELS The default setting for the vertical tick labels flag.
[Expand]
Inherited Constants
From class org.jfree.chart.axis.ValueAxis
From class org.jfree.chart.axis.Axis
Fields
public static final NumberTickUnit DEFAULT_TICK_UNIT The default tick unit.
[Expand]
Inherited Fields
From class org.jfree.chart.axis.ValueAxis
From class org.jfree.chart.axis.Axis
Public Constructors
NumberAxis()
Default constructor.
NumberAxis(String label)
Constructs a number axis, using default values where necessary.
Public Methods
Object clone()
Returns a clone of the axis.
void configure()
Configures the axis to work with the specified plot.
static TickUnitSource createIntegerTickUnits(Locale locale)
Returns a collection of tick units for integer values.
static TickUnitSource createIntegerTickUnits()
Returns a collection of tick units for integer values.
static TickUnitSource createStandardTickUnits()
Creates the standard tick units.
static TickUnitSource createStandardTickUnits(Locale locale)
Creates a collection of standard tick units.
AxisState draw(Graphics2D g2, double cursor, Rectangle2D plotArea, Rectangle2D dataArea, RectangleEdge edge, PlotRenderingInfo plotState)
Draws the axis on a Java 2D graphics device (such as the screen or a printer).
boolean equals(Object obj)
Tests the axis for equality with an arbitrary object.
boolean getAutoRangeIncludesZero()
Returns the flag that indicates whether or not the automatic axis range (if indeed it is determined automatically) is forced to include zero.
boolean getAutoRangeStickyZero()
Returns a flag that affects the auto-range when zero falls outside the data range but inside the margins defined for the axis.
MarkerAxisBand getMarkerBand()
Returns the (optional) marker band for the axis.
NumberFormat getNumberFormatOverride()
Returns the number format override.
RangeType getRangeType()
Returns the axis range type.
NumberTickUnit getTickUnit()
Returns the tick unit for the axis.
int hashCode()
Returns a hash code for this object.
double java2DToValue(double java2DValue, Rectangle2D area, RectangleEdge edge)
Converts a coordinate in Java2D space to the corresponding data value, assuming that the axis runs along one edge of the specified dataArea.
List refreshTicks(Graphics2D g2, AxisState state, Rectangle2D dataArea, RectangleEdge edge)
Calculates the positions of the tick labels for the axis, storing the results in the tick label list (ready for drawing).
void setAutoRangeIncludesZero(boolean flag)
Sets the flag that indicates whether or not the axis range, if automatically calculated, is forced to include zero.
void setAutoRangeStickyZero(boolean flag)
Sets a flag that affects the auto-range when zero falls outside the data range but inside the margins defined for the axis.
void setMarkerBand(MarkerAxisBand band)
Sets the marker band for the axis.
void setNumberFormatOverride(NumberFormat formatter)
Sets the number format override.
void setRangeType(RangeType rangeType)
Sets the axis range type.
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, Rectangle2D area, RectangleEdge edge)
Converts a data value to a coordinate in Java2D space, assuming that the axis runs along one edge of the specified dataArea.
Protected Methods
void autoAdjustRange()
Rescales the axis to ensure that all data is visible.
double calculateHighestVisibleTickValue()
Calculates the value of the highest visible tick on the axis.
double calculateLowestVisibleTickValue()
Calculates the value of the lowest visible tick on the axis.
int calculateVisibleTickCount()
Calculates the number of visible ticks.
double estimateMaximumTickLabelHeight(Graphics2D g2)
Estimates the maximum tick label height.
double estimateMaximumTickLabelWidth(Graphics2D g2, TickUnit unit)
Estimates the maximum width of the tick labels, assuming the specified tick unit is used.
List refreshTicksHorizontal(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Calculates the positions of the tick labels for the axis, storing the results in the tick label list (ready for drawing).
List refreshTicksVertical(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Calculates the positions of the tick labels for the axis, storing the results in the tick label list (ready for drawing).
void selectAutoTickUnit(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Selects an appropriate tick value for the axis.
void selectHorizontalAutoTickUnit(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Selects an appropriate tick value for the axis.
void selectVerticalAutoTickUnit(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Selects an appropriate tick value for the axis.
[Expand]
Inherited Methods
From class org.jfree.chart.axis.ValueAxis
From class org.jfree.chart.axis.Axis
From class java.lang.Object

Constants

public static final boolean DEFAULT_AUTO_RANGE_INCLUDES_ZERO

The default value for the autoRangeIncludesZero flag.

Constant Value: true

public static final boolean DEFAULT_AUTO_RANGE_STICKY_ZERO

The default value for the autoRangeStickyZero flag.

Constant Value: true

public static final boolean DEFAULT_VERTICAL_TICK_LABELS

The default setting for the vertical tick labels flag.

Constant Value: false

Fields

public static final NumberTickUnit DEFAULT_TICK_UNIT

The default tick unit.

Public Constructors

public NumberAxis ()

Default constructor.

public NumberAxis (String label)

Constructs a number axis, using default values where necessary.

Parameters
label the axis label (null permitted).

Public Methods

public Object clone ()

Returns a clone of the axis.

Returns
  • A clone
Throws
CloneNotSupportedException if some component of the axis does not support cloning.

public void configure ()

Configures the axis to work with the specified plot. If the axis has auto-scaling, then sets the maximum and minimum values.

public static TickUnitSource createIntegerTickUnits (Locale locale)

Returns a collection of tick units for integer 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.
See Also

public static TickUnitSource createIntegerTickUnits ()

Returns a collection of tick units for integer values.

Returns
  • A collection of tick units for integer values.
See Also

public static TickUnitSource createStandardTickUnits ()

Creates the standard tick units.

If you don't like these defaults, create your own instance of TickUnits and then pass it to the setStandardTickUnits() method in the NumberAxis class.

Returns
  • The standard tick units.
See Also

public static TickUnitSource createStandardTickUnits (Locale locale)

Creates a collection of standard tick units. The supplied locale is used to create the number formatter (a localised instance of NumberFormat).

If you don't like these defaults, create your own instance of TickUnits and then pass it to the setStandardTickUnits() method.

Parameters
locale the locale.
Returns
  • A tick unit collection.
See Also

public AxisState draw (Graphics2D g2, double cursor, Rectangle2D plotArea, Rectangle2D dataArea, RectangleEdge edge, PlotRenderingInfo plotState)

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

Parameters
g2 the graphics device (null not permitted).
cursor the cursor location.
plotArea the area within which the axes and data should be drawn (null not permitted).
dataArea the area within which the data should be drawn (null not permitted).
edge the location of the axis (null not permitted).
plotState collects information about the plot (null permitted).
Returns
  • The axis state (never null).

public boolean equals (Object obj)

Tests the axis for equality with an arbitrary object.

Parameters
obj the object (null permitted).
Returns
  • A boolean.

public boolean getAutoRangeIncludesZero ()

Returns the flag that indicates whether or not the automatic axis range (if indeed it is determined automatically) is forced to include zero.

Returns
  • The flag.

public boolean getAutoRangeStickyZero ()

Returns a flag that affects the auto-range when zero falls outside the data range but inside the margins defined for the axis.

Returns
  • The flag.
See Also

public MarkerAxisBand getMarkerBand ()

Returns the (optional) marker band for the axis.

Returns
  • The marker band (possibly null).
See Also

public 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

public RangeType getRangeType ()

Returns the axis range type.

Returns
  • The axis range type (never null).
See Also

public NumberTickUnit getTickUnit ()

Returns the tick unit for the axis.

Note: if the autoTickUnitSelection flag is true the tick unit may be changed while the axis is being drawn, so in that case the return value from this method may be irrelevant if the method is called before the axis has been drawn.

Returns
  • The tick unit for the axis.
See Also

public int hashCode ()

Returns a hash code for this object.

Returns
  • A hash code.

public double java2DToValue (double java2DValue, Rectangle2D area, RectangleEdge edge)

Converts a coordinate in Java2D space to the corresponding data value, assuming that the axis runs along one edge of the specified dataArea.

Parameters
java2DValue the coordinate in Java2D space.
area the area in which the data is plotted.
edge the location.
Returns
  • The data value.
See Also

public List refreshTicks (Graphics2D g2, AxisState state, Rectangle2D dataArea, RectangleEdge edge)

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

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.

public void setAutoRangeIncludesZero (boolean flag)

Sets the flag that indicates whether or not the axis range, if automatically calculated, is forced to include zero.

If the flag is changed to true, the axis range is recalculated.

Any change to the flag will trigger an AxisChangeEvent.

Parameters
flag the new value of the flag.
See Also

public void setAutoRangeStickyZero (boolean flag)

Sets a flag that affects the auto-range when zero falls outside the data range but inside the margins defined for the axis.

Parameters
flag the new flag.
See Also

public void setMarkerBand (MarkerAxisBand band)

Sets the marker band for the axis.

The marker band is optional, leave it set to null if you don't require it.

Parameters
band the new band (null permitted).
See Also

public void setNumberFormatOverride (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

public void setRangeType (RangeType rangeType)

Sets the axis range type.

Parameters
rangeType the range type (null not permitted).
See Also

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 setAutoTickUnitSelection(boolean) method).

Parameters
unit the new tick unit (null not permitted).
See Also

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 setAutoTickUnitSelection(boolean) method).

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

public double valueToJava2D (double value, Rectangle2D area, RectangleEdge edge)

Converts a data value to a coordinate in Java2D space, assuming that the axis runs along one edge of the specified dataArea.

Note that it is possible for the coordinate to fall outside the plotArea.

Parameters
value the data value.
area the area for plotting the data.
edge the axis location.
Returns
  • The Java2D coordinate.
See Also

Protected Methods

protected void autoAdjustRange ()

Rescales the axis to ensure that all data is visible.

protected double calculateHighestVisibleTickValue ()

Calculates the value of the highest visible tick on the axis.

Returns
  • The value of the highest visible tick on the axis.
See Also

protected double calculateLowestVisibleTickValue ()

Calculates the value of the lowest visible tick on the axis.

Returns
  • The value of the lowest visible tick on the axis.
See Also

protected int calculateVisibleTickCount ()

Calculates the number of visible ticks.

Returns
  • The number of visible ticks on the axis.

protected double estimateMaximumTickLabelHeight (Graphics2D g2)

Estimates the maximum tick label height.

Parameters
g2 the graphics device.
Returns
  • The maximum height.

protected double estimateMaximumTickLabelWidth (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.

protected List refreshTicksHorizontal (Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)

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

Parameters
g2 the graphics device.
dataArea the area in which the data should be drawn.
edge the location of the axis.
Returns
  • A list of ticks.

protected List refreshTicksVertical (Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)

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

Parameters
g2 the graphics device.
dataArea the area in which the plot should be drawn.
edge the location of the axis.
Returns
  • A list of ticks.

protected void selectAutoTickUnit (Graphics2D g2, Rectangle2D dataArea, 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.

protected void selectHorizontalAutoTickUnit (Graphics2D g2, Rectangle2D dataArea, 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.

protected void selectVerticalAutoTickUnit (Graphics2D g2, Rectangle2D dataArea, 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.