org.jfree.chart.axis

Class NumberAxis

public class NumberAxis extends ValueAxis implements Cloneable, Serializable

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.

Field Summary
static booleanDEFAULT_AUTO_RANGE_INCLUDES_ZERO
The default value for the autoRangeIncludesZero flag.
static booleanDEFAULT_AUTO_RANGE_STICKY_ZERO
The default value for the autoRangeStickyZero flag.
static NumberTickUnitDEFAULT_TICK_UNIT
The default tick unit.
static booleanDEFAULT_VERTICAL_TICK_LABELS
The default setting for the vertical tick labels flag.
Constructor Summary
NumberAxis()
Default constructor.
NumberAxis(String label)
Constructs a number axis, using default values where necessary.
Method Summary
protected voidautoAdjustRange()
Rescales the axis to ensure that all data is visible.
protected doublecalculateHighestVisibleTickValue()
Calculates the value of the highest visible tick on the axis.
protected doublecalculateLowestVisibleTickValue()
Calculates the value of the lowest visible tick on the axis.
protected intcalculateVisibleTickCount()
Calculates the number of visible ticks.
Objectclone()
Returns a clone of the axis.
voidconfigure()
Configures the axis to work with the specified plot.
static TickUnitSourcecreateIntegerTickUnits()
Returns a collection of tick units for integer values.
static TickUnitSourcecreateIntegerTickUnits(Locale locale)
Returns a collection of tick units for integer values.
static TickUnitSourcecreateStandardTickUnits()
Creates the standard tick units.
static TickUnitSourcecreateStandardTickUnits(Locale locale)
Creates a collection of standard tick units.
AxisStatedraw(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).
booleanequals(Object obj)
Tests the axis for equality with an arbitrary object.
protected doubleestimateMaximumTickLabelHeight(Graphics2D g2)
Estimates the maximum tick label height.
protected doubleestimateMaximumTickLabelWidth(Graphics2D g2, TickUnit unit)
Estimates the maximum width of the tick labels, assuming the specified tick unit is used.
booleangetAutoRangeIncludesZero()
Returns the flag that indicates whether or not the automatic axis range (if indeed it is determined automatically) is forced to include zero.
booleangetAutoRangeStickyZero()
Returns a flag that affects the auto-range when zero falls outside the data range but inside the margins defined for the axis.
MarkerAxisBandgetMarkerBand()
Returns the (optional) marker band for the axis.
NumberFormatgetNumberFormatOverride()
Returns the number format override.
RangeTypegetRangeType()
Returns the axis range type.
NumberTickUnitgetTickUnit()
Returns the tick unit for the axis.
inthashCode()
Returns a hash code for this object.
doublejava2DToValue(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.
ListrefreshTicks(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).
protected ListrefreshTicksHorizontal(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).
protected ListrefreshTicksVertical(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).
protected voidselectAutoTickUnit(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Selects an appropriate tick value for the axis.
protected voidselectHorizontalAutoTickUnit(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Selects an appropriate tick value for the axis.
protected voidselectVerticalAutoTickUnit(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Selects an appropriate tick value for the axis.
voidsetAutoRangeIncludesZero(boolean flag)
Sets the flag that indicates whether or not the axis range, if automatically calculated, is forced to include zero.
voidsetAutoRangeStickyZero(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.
voidsetMarkerBand(MarkerAxisBand band)
Sets the marker band for the axis.
voidsetNumberFormatOverride(NumberFormat formatter)
Sets the number format override.
voidsetRangeType(RangeType rangeType)
Sets the axis range type.
voidsetTickUnit(NumberTickUnit unit)
Sets the tick unit for the axis and sends an AxisChangeEvent to all registered listeners.
voidsetTickUnit(NumberTickUnit unit, boolean notify, boolean turnOffAutoSelect)
Sets the tick unit for the axis and, if requested, sends an AxisChangeEvent to all registered listeners.
doublevalueToJava2D(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.

Field Detail

DEFAULT_AUTO_RANGE_INCLUDES_ZERO

public static final boolean DEFAULT_AUTO_RANGE_INCLUDES_ZERO
The default value for the autoRangeIncludesZero flag.

DEFAULT_AUTO_RANGE_STICKY_ZERO

public static final boolean DEFAULT_AUTO_RANGE_STICKY_ZERO
The default value for the autoRangeStickyZero flag.

DEFAULT_TICK_UNIT

public static final NumberTickUnit DEFAULT_TICK_UNIT
The default tick unit.

DEFAULT_VERTICAL_TICK_LABELS

public static final boolean DEFAULT_VERTICAL_TICK_LABELS
The default setting for the vertical tick labels flag.

Constructor Detail

NumberAxis

public NumberAxis()
Default constructor.

NumberAxis

public NumberAxis(String label)
Constructs a number axis, using default values where necessary.

Parameters: label the axis label (null permitted).

Method Detail

autoAdjustRange

protected void autoAdjustRange()
Rescales the axis to ensure that all data is visible.

calculateHighestVisibleTickValue

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: calculateLowestVisibleTickValue

calculateLowestVisibleTickValue

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: calculateHighestVisibleTickValue

calculateVisibleTickCount

protected int calculateVisibleTickCount()
Calculates the number of visible ticks.

Returns: The number of visible ticks on the axis.

clone

public Object clone()
Returns a clone of the axis.

Returns: A clone

Throws: CloneNotSupportedException if some component of the axis does not support cloning.

configure

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.

createIntegerTickUnits

public static TickUnitSource createIntegerTickUnits()
Returns a collection of tick units for integer values.

Returns: A collection of tick units for integer values.

See Also: NumberAxis createStandardTickUnits

createIntegerTickUnits

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: NumberAxis

createStandardTickUnits

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: NumberAxis createIntegerTickUnits

createStandardTickUnits

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: NumberAxis

draw

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).

equals

public boolean equals(Object obj)
Tests the axis for equality with an arbitrary object.

Parameters: obj the object (null permitted).

Returns: A boolean.

estimateMaximumTickLabelHeight

protected double estimateMaximumTickLabelHeight(Graphics2D g2)
Estimates the maximum tick label height.

Parameters: g2 the graphics device.

Returns: The maximum height.

estimateMaximumTickLabelWidth

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.

getAutoRangeIncludesZero

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.

getAutoRangeStickyZero

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: NumberAxis

getMarkerBand

public MarkerAxisBand getMarkerBand()
Returns the (optional) marker band for the axis.

Returns: The marker band (possibly null).

See Also: setMarkerBand

getNumberFormatOverride

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: setNumberFormatOverride

getRangeType

public RangeType getRangeType()
Returns the axis range type.

Returns: The axis range type (never null).

See Also: setRangeType

getTickUnit

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: setTickUnit isAutoTickUnitSelection

hashCode

public int hashCode()
Returns a hash code for this object.

Returns: A hash code.

java2DToValue

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: NumberAxis

refreshTicks

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.

refreshTicksHorizontal

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.

refreshTicksVertical

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.

selectAutoTickUnit

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.

selectHorizontalAutoTickUnit

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.

selectVerticalAutoTickUnit

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.

setAutoRangeIncludesZero

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: getAutoRangeIncludesZero

setAutoRangeStickyZero

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: getAutoRangeStickyZero

setMarkerBand

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: getMarkerBand

setNumberFormatOverride

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: getNumberFormatOverride

setRangeType

public void setRangeType(RangeType rangeType)
Sets the axis range type.

Parameters: rangeType the range type (null not permitted).

See Also: getRangeType

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 method).

Parameters: unit the new tick unit (null not permitted).

See Also: getTickUnit NumberAxis

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 method).

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

valueToJava2D

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: NumberAxis

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