org.jfree.chart.axis

Class LogAxis

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

Constructor Summary
LogAxis()
Creates a new LogAxis with no label.
LogAxis(String label)
Creates a new LogAxis with the given label.
Method Summary
protected voidautoAdjustRange()
Adjusts the axis range to match the data range that the axis is required to display.
doublecalculateLog(double value)
Calculates the log of the given value, using the current base.
doublecalculateValue(double log)
Calculates the value from a given log.
voidconfigure()
Configures the axis.
static TickUnitSourcecreateLogTickUnits(Locale locale)
Returns a collection of tick units for log (base 10) values.
protected StringcreateTickLabel(double value)
Creates a tick label for the specified value.
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 this 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.
doubleexponentLengthToJava2D(double length, Rectangle2D area, RectangleEdge edge)
Converts a length in data coordinates into the corresponding length in Java2D coordinates.
doublegetBase()
Returns the base for the logarithm calculation.
NumberFormatgetNumberFormatOverride()
Returns the number format override.
doublegetSmallestValue()
Returns the smallest value represented by the axis.
NumberTickUnitgetTickUnit()
Returns the current tick unit.
inthashCode()
Returns a hash code for this instance.
doublejava2DToValue(double java2DValue, Rectangle2D area, RectangleEdge edge)
Converts a Java2D coordinate to an axis value, assuming that the axis covers the specified edge of the area.
voidpan(double percent)
Slides the axis range by the specified percentage.
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)
Returns a list of ticks for an axis at the top or bottom of the chart.
protected ListrefreshTicksVertical(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge)
Returns a list of ticks for an axis at the left or right of the chart.
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.
voidsetBase(double base)
Sets the base for the logarithm calculation and sends an AxisChangeEvent to all registered listeners.
voidsetNumberFormatOverride(NumberFormat formatter)
Sets the number format override.
voidsetSmallestValue(double value)
Sets the smallest value represented by the axis and sends an AxisChangeEvent to all registered listeners.
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 value on the axis scale to a Java2D coordinate relative to the given area, based on the axis running along the specified edge.
voidzoomRange(double lowerPercent, double upperPercent)
Zooms in on the current range.

Constructor Detail

LogAxis

public LogAxis()
Creates a new LogAxis with no label.

LogAxis

public LogAxis(String label)
Creates a new LogAxis with the given label.

Parameters: label the axis label (null permitted).

Method Detail

autoAdjustRange

protected void autoAdjustRange()
Adjusts the axis range to match the data range that the axis is required to display.

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: LogAxis 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: LogAxis getBase

configure

public void configure()
Configures the axis. This method is typically called when an axis is assigned to a new plot.

createLogTickUnits

public static TickUnitSource createLogTickUnits(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

createTickLabel

protected 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

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 (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).

equals

public boolean equals(Object obj)
Tests this 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.

Since: 1.0.7

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.

Since: 1.0.7

exponentLengthToJava2D

public double exponentLengthToJava2D(double length, Rectangle2D area, 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

getBase

public double getBase()
Returns the base for the logarithm calculation.

Returns: The base for the logarithm calculation.

See Also: LogAxis

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

getSmallestValue

public double getSmallestValue()
Returns the smallest value represented by the axis.

Returns: The smallest value represented by the axis.

See Also: LogAxis

getTickUnit

public NumberTickUnit getTickUnit()
Returns the current tick unit.

Returns: The current tick unit.

See Also: setTickUnit

hashCode

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

Returns: A hash code.

java2DToValue

public double java2DToValue(double java2DValue, Rectangle2D area, RectangleEdge edge)
Converts a Java2D coordinate to an axis value, assuming that the axis covers the specified edge of the area.

Parameters: java2DValue the Java2D coordinate. area the area. edge the edge that the axis belongs to.

Returns: A value along the axis scale.

pan

public void pan(double percent)
Slides the axis range by the specified percentage.

Parameters: percent the percentage.

Since: 1.0.13

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)
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 List refreshTicksVertical(Graphics2D g2, Rectangle2D dataArea, 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(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.

Since: 1.0.7

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.

Since: 1.0.7

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.

Since: 1.0.7

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

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

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

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

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?

See Also: getTickUnit

valueToJava2D

public double valueToJava2D(double value, Rectangle2D area, 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.

Parameters: value the data value. area the area. edge the edge.

Returns: The Java2D coordinate corresponding to value.

zoomRange

public void zoomRange(double lowerPercent, double upperPercent)
Zooms in on the current range.

Parameters: lowerPercent the new lower bound. upperPercent the new upper bound.

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