com.approximatrix.charting
Class CoordSystemUtilities

java.lang.Object
  com.approximatrix.charting.CoordSystemUtilities

public class CoordSystemUtilities
extends java.lang.Object

This class provides some utility functions for a CoordSystem. They were externalized to make the CoordSystem class clearer.

Version:

1.0

Author:

mueller, armstrong

Field Summary

protected CoordSystem	c The coordinate system associated with these utilities
protected ChartDataModelConstraints	constraints The primary axis constraints
protected ChartDataModelConstraints	constraints2 The secondary axis contraints
private static int	DEFAULT_MAX_ACTUAL_TICKS The default maximum number of ticks to allow the tick position calculator to generate on a single axis.
private static float[]	DOT1 Constant array of floats used to create the default grid line style.
private int	estimated_x_ticks Estimate of the number of x ticks to draw.
private int	estimated_y_ticks Estimates of the number of y ticks to draw.
private static java.awt.Color	GRID_COLOR Color used for drawing gridlines
private static java.awt.BasicStroke	GRID_LINE_STYLE Default and fixed grid line style to use
protected int	leftUnitBuffer Buffer to move the y axis label off the absolute bounds
protected int	marginOffset used for the offset on the y axis for the size of a "tick"
private static int	MAX Internal constant refering to the max value index of a 2-element constraint array
private int	maximum_x_ticks The maximum number of x ticks to allow in the x direction
private int	maximum_y_ticks The maximum number of y ticks to allow in the x direction
private static int	MIN Internal constant refering to the min value index of a 2-element constraint array
protected ChartDataModel	model The model associated with these utilities
private static int	SIMPLE_TICK_THRESHOLD The threshhold of specified tic mark counts at which the routines default to simple tick mark calculator
private static int	STOP_TICK_RECURSIONS Count of recursions into the tick mark auto-placement routine at which to give up calculating placement
private int	tick_recursions Used to limit the number of recursions into the tick mark auto-placement routine

Constructor Summary

CoordSystemUtilities(CoordSystem coord, ChartDataModelConstraints constraints, ChartDataModelConstraints constraints2, ChartDataModel model)
Creates a new instance of CoordSystemUtilities

Method Summary

private void	checkMaxTickConsistency() Makes sure that the estimated tic mark count is always limited by the maximum tic mark count limit.
int	computeBottomMargin() Computes the bottom margin.
int	computeLeftMargin() Computes the left margin.
int	computeRightMargin() Computes the right margin.
private double[]	computeTicMarkLocations(double max, double min, int numTicsDesired, int maxTics) Simple wrapper that calls the other computeTicMarkLocations routine.
private double[]	computeTicMarkLocations(double max, double min, int numTicsDesired, int maxTics, boolean force_simple) Simple wrapper routine that calls the appropriate tic mark locator routine.
int	computeTopMargin() Computes the top margin.
int	computeXAxisLabelHeight() Computes the maximum height of all x-axis labels.
int	computeYAxisLabelWidth() Computes the maximum width of all y-axis labels.
void	drawNumericalXAxisGrid(java.awt.Graphics2D g) Draws a grid based on values in the x-axis
void	drawNumericalXAxisTicks(java.awt.Graphics2D g) This method is called by paintDefault to paint the ticks on the x-axis for numerical x-axis values.
void	drawXAxisTicks(java.awt.Graphics2D g) This method is called by paintDefault to paint the ticks on the x-axis for non-numerical x-axis values..
void	drawYAxisGrid(java.awt.Graphics2D g) Draws a grid based on values in the y-axis
void	drawYAxisTicks(java.awt.Graphics2D g) This method is called by paintDefault to paint the ticks on the y-axis.
int	getEstimatedXTicks() Returns the number of estimated X ticks to draw on the graph (not the actual)
int	getEstimatedYTicks() Returns the number of estimated Y ticks to draw on the graph (not the actual)
int	getMaximumXTicks() Returns the maximum number of X ticks to draw on the X axis
int	getMaximumYTicks() Returns the maximum number of Y ticks to draw on the Y axis
java.awt.geom.Line2D	getSecondYAxisLine2D() Computes the Line2D object of the second y-axis using the DataConstraints.
java.awt.geom.Line2D	getXAxisLine2D() Computes the Line2D object of the x-axis using the DataConstraints.
private java.awt.geom.Point2D[]	getXTickLocations() Returns the location of tick marks on the x-axis without any transform for plotting
java.awt.geom.Line2D	getYAxisLine2D() Computes the Line2D object of the y-axis using the DataConstraints.
private java.awt.geom.Point2D[]	getYTickLocations() Returns the location of tick marks on the y-axis without any transform for plotting
private double[]	performAutoScale(double max, double min, int numTicsDesired, int maxTics) Computes the tick mark locations on an axis
private double[]	safeMaxMin(double max, double min) Returns a safe estimate of min and max drawing values for an axis.
void	setEstimatedXTicks(int number) Sets the estimated number of X ticks (not the actual - handled by autoscaler)
void	setEstimatedYTicks(int number) Sets the estimated number of Y ticks (not the actual - handled by autoscaler)
void	setMaximumXTicks(int value)
void	setMaximumYTicks(int value) Sets the maximum number of ticks along the Y axis that will be allowed.
private double[]	simpleTics(double max, double min, int numTicsDesired) Foolproof and simple method for determining Tic placement in cases where the tic count is low theoretically.

Methods inherited from class java.lang.Object

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

Field Detail

MAX

private static final int MAX

Internal constant refering to the max value index of a 2-element constraint array

See Also:

Constant Field Values

MIN

private static final int MIN

Internal constant refering to the min value index of a 2-element constraint array

See Also:

Constant Field Values

GRID_COLOR

private static final java.awt.Color GRID_COLOR

Color used for drawing gridlines

DOT1

private static final float[] DOT1

Constant array of floats used to create the default grid line style.

GRID_LINE_STYLE

private static final java.awt.BasicStroke GRID_LINE_STYLE

Default and fixed grid line style to use

marginOffset

protected final int marginOffset

used for the offset on the y axis for the size of a "tick"

See Also:

Constant Field Values

leftUnitBuffer

protected final int leftUnitBuffer

Buffer to move the y axis label off the absolute bounds

See Also:

Constant Field Values

c

protected CoordSystem c

The coordinate system associated with these utilities

constraints

protected ChartDataModelConstraints constraints

The primary axis constraints

constraints2

protected ChartDataModelConstraints constraints2

The secondary axis contraints

model

protected ChartDataModel model

The model associated with these utilities

estimated_x_ticks

private int estimated_x_ticks

Estimate of the number of x ticks to draw. Used for evaluating the automatically-generated tick locations.

estimated_y_ticks

private int estimated_y_ticks

Estimates of the number of y ticks to draw. Used for evaluating the automatically-generated tick locations.

DEFAULT_MAX_ACTUAL_TICKS

private static final int DEFAULT_MAX_ACTUAL_TICKS

The default maximum number of ticks to allow the tick position calculator to generate on a single axis.

See Also:

Constant Field Values

maximum_x_ticks

private int maximum_x_ticks

The maximum number of x ticks to allow in the x direction

maximum_y_ticks

private int maximum_y_ticks

The maximum number of y ticks to allow in the x direction

SIMPLE_TICK_THRESHOLD

private static final int SIMPLE_TICK_THRESHOLD

The threshhold of specified tic mark counts at which the routines default to simple tick mark calculator

See Also:

Constant Field Values

tick_recursions

private int tick_recursions

Used to limit the number of recursions into the tick mark auto-placement routine

STOP_TICK_RECURSIONS

private static final int STOP_TICK_RECURSIONS

Count of recursions into the tick mark auto-placement routine at which to give up calculating placement

See Also:

Constant Field Values

Constructor Detail

CoordSystemUtilities

public CoordSystemUtilities(CoordSystem coord,
                            ChartDataModelConstraints constraints,
                            ChartDataModelConstraints constraints2,
                            ChartDataModel model)

Creates a new instance of CoordSystemUtilities

Method Detail

computeLeftMargin

public int computeLeftMargin()

Computes the left margin.

computeRightMargin

public int computeRightMargin()

Computes the right margin.

computeTopMargin

public int computeTopMargin()

Computes the top margin.

computeBottomMargin

public int computeBottomMargin()

Computes the bottom margin.

computeXAxisLabelHeight

public int computeXAxisLabelHeight()

Computes the maximum height of all x-axis labels.

computeYAxisLabelWidth

public int computeYAxisLabelWidth()

Computes the maximum width of all y-axis labels.

drawNumericalXAxisTicks

public void drawNumericalXAxisTicks(java.awt.Graphics2D g)

This method is called by paintDefault to paint the ticks on the x-axis for numerical x-axis values.

Parameters:

g - the Graphics2D context to paint in

drawXAxisTicks

public void drawXAxisTicks(java.awt.Graphics2D g)

This method is called by paintDefault to paint the ticks on the x-axis for non-numerical x-axis values..

Parameters:

g - the Graphics2D context to paint in

drawYAxisTicks

public void drawYAxisTicks(java.awt.Graphics2D g)

This method is called by paintDefault to paint the ticks on the y-axis.

Parameters:

g - the Graphics2D context in which to draw

drawYAxisGrid

public void drawYAxisGrid(java.awt.Graphics2D g)

Draws a grid based on values in the y-axis

drawNumericalXAxisGrid

public void drawNumericalXAxisGrid(java.awt.Graphics2D g)

Draws a grid based on values in the x-axis

getYTickLocations

private java.awt.geom.Point2D[] getYTickLocations()

Returns the location of tick marks on the y-axis without any transform for plotting

getXTickLocations

private java.awt.geom.Point2D[] getXTickLocations()

Returns the location of tick marks on the x-axis without any transform for plotting

getXAxisLine2D

public java.awt.geom.Line2D getXAxisLine2D()

Computes the Line2D object of the x-axis using the DataConstraints.

getYAxisLine2D

public java.awt.geom.Line2D getYAxisLine2D()

Computes the Line2D object of the y-axis using the DataConstraints.

getSecondYAxisLine2D

public java.awt.geom.Line2D getSecondYAxisLine2D()

Computes the Line2D object of the second y-axis using the DataConstraints.

computeTicMarkLocations

private double[] computeTicMarkLocations(double max,
                                         double min,
                                         int numTicsDesired,
                                         int maxTics)

Simple wrapper that calls the other computeTicMarkLocations routine. This wrapper does not require the specification of the force_simple flag. This routine may become deprecated in the future if the option to always force simple tic mark calculation is added.

Parameters:

max - the largest value to be plotted

min - the smallest value to be plotted

numTicsDesired - the approximate desired number of tics (the result may not be this number of tics)

maxTics - the absolute maximum number of tics to draw

Returns:

positions of tick marks along the axis

computeTicMarkLocations

private double[] computeTicMarkLocations(double max,
                                         double min,
                                         int numTicsDesired,
                                         int maxTics,
                                         boolean force_simple)

Simple wrapper routine that calls the appropriate tic mark locator routine. The algorithm used depends on the desired number of tick marks to draw on the chart. If the requested number of tics than 5, the library will default to drawing using the simpleTic routine (which does not attempt to generate rounded numerical values). Any other values calls the elaborate tic calculator performAutoScale.

Parameters:

max - the largest value to be plotted

min - the smallest value to be plotted

numTicsDesired - the approximate desired number of tics (the result may not be this number of tics)

maxTics - the absolute maximum number of tics to draw

force_simple - force the use of the simple algorithm for drawing tic marks

Returns:

positions of tick marks along the axis

simpleTics

private double[] simpleTics(double max,
                            double min,
                            int numTicsDesired)

Foolproof and simple method for determining Tic placement in cases where the tic count is low theoretically. Simply creates equidistant tic marks based on the max, min and the number of tics desired inputs. No consideration is given to how nice the tic marks will look; the routine simply partitions the tic marks equally based on the span.

Parameters:

max - the largest value to be plotted

min - the smallest value to be plotted

numTicsDesired - the exact number of tics desired

Returns:

unrounded positions of tick marks along the axis

performAutoScale

private double[] performAutoScale(double max,
                                  double min,
                                  int numTicsDesired,
                                  int maxTics)

Computes the tick mark locations on an axis

Parameters:

max - the largest value in a data set

min - the smallest value in a data set

numTicsDesired - the first guess at the number of desired tick marks

Returns:

positions of tick marks along the axis

setEstimatedXTicks

public void setEstimatedXTicks(int number)

Sets the estimated number of X ticks (not the actual - handled by autoscaler)

Parameters:

number - the number of xticks to draw (estimated)

setEstimatedYTicks

public void setEstimatedYTicks(int number)

Sets the estimated number of Y ticks (not the actual - handled by autoscaler)

Parameters:

number - the number of yticks to draw (estimated)

getEstimatedXTicks

public int getEstimatedXTicks()

Returns the number of estimated X ticks to draw on the graph (not the actual)

Returns:

the estimated number of ticks to be drawn

getEstimatedYTicks

public int getEstimatedYTicks()

Returns the number of estimated Y ticks to draw on the graph (not the actual)

Returns:

the estimated number of ticks to be drawn

setMaximumXTicks

public void setMaximumXTicks(int value)

Parameters:

value -

setMaximumYTicks

public void setMaximumYTicks(int value)

Sets the maximum number of ticks along the Y axis that will be allowed.

Parameters:

value - the maximum number of Y ticks, or -1 to reset to default

getMaximumXTicks

public int getMaximumXTicks()

Returns the maximum number of X ticks to draw on the X axis

Returns:

the maximum number of X ticks to draw

getMaximumYTicks

public int getMaximumYTicks()

Returns the maximum number of Y ticks to draw on the Y axis

Returns:

the maximum number of Y ticks to draw

checkMaxTickConsistency

private void checkMaxTickConsistency()

Makes sure that the estimated tic mark count is always limited by the maximum tic mark count limit. Should be called every time the setEstimated?Ticks or setMaximum?Ticks methods are run.

safeMaxMin

private double[] safeMaxMin(double max,
                            double min)

Returns a safe estimate of min and max drawing values for an axis. Used to defend against special cases where max and min might be equal or reversed.

Parameters:

max - the original max value

min - the originial min value

Returns:

the new max and min values in an array, which can be indexed using the MAX and MIN constants in this class