Package org.opensourcephysics.display

Class FunctionDrawer

java.lang.Object

org.opensourcephysics.display.FunctionDrawer

All Implemented Interfaces:

Drawable, Measurable, Function

public class FunctionDrawer
extends java.lang.Object
implements Drawable, Measurable, Function

FunctionDrawer draws a function from xmin to xmax. The function will be evaluated at every screen pixel unless the domain is set using the initialize method.

Field Summary

Fields

Modifier and Type	Field	Description
java.awt.Color	color
protected boolean	filled
protected Function	function
boolean	functionChanged
protected java.awt.geom.GeneralPath	generalPath
protected boolean	measured
protected int	numpts
protected double[]	xrange
protected double[]	yrange

Constructor Summary

Constructors

Constructor	Description
FunctionDrawer(Function f)	Contstucts a FunctionDrawer with optimum resolution.
FunctionDrawer(Function f, double xmin, double xmax, int numpts, boolean filled)	Creates the function drawer and initialzies the domain with the given values.

Method Summary

Modifier and Type	Method	Description
protected void	checkRange(DrawingPanel panel)
void	draw(DrawingPanel panel, java.awt.Graphics g)	Draw the function on a drawing panel.
double	evaluate(double x)	Evalutes the function.
java.awt.geom.GeneralPath	getPath()	Gets the general path that draws this function.
double	getXMax()	Gets the maximum x needed to draw this object.
double	getXMin()	Gets the minimum x needed to draw this object.
double[]	getXRange()	Get the range of x values over which the function has been evaluated.
double	getYMax()	Gets the maximum y needed to draw this object.
double	getYMin()	Gets the minimum y needed to draw this object.
double[]	getYRange()	Get the minimum and maximum y values for the function.
void	initialize(double xmin, double xmax, int numpts, boolean filled)	Initialize the function range and the number of display points.
boolean	isMeasured()	Determines if information is available to set min/max values.
void	setColor(java.awt.Color c)	Sets the drawing color.
void	setFilled(boolean _filled)	Fills the area under the curve when true.

Methods inherited from class java.lang.Object

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

Field Detail

xrange

protected double[] xrange

yrange

protected double[] yrange

numpts

protected int numpts

generalPath

protected java.awt.geom.GeneralPath generalPath

function

protected Function function

filled

protected boolean filled

measured

protected boolean measured

color

public java.awt.Color color

functionChanged

public boolean functionChanged

Constructor Detail

FunctionDrawer

public FunctionDrawer(Function f)

Contstucts a FunctionDrawer with optimum resolution.

Parameters:

f - the function that will be drawn.

FunctionDrawer

public FunctionDrawer(Function f,
                      double xmin,
                      double xmax,
                      int numpts,
                      boolean filled)

Creates the function drawer and initialzies the domain with the given values.

Parameters:

f - Function

xmin - double

xmax - double

numpts - int

filled - boolean fills the area under the curve with the drawing color when true

Method Detail

evaluate

public double evaluate(double x)

Evalutes the function.

Specified by:

evaluate in interface Function

Parameters:

x -

Returns:

value of the function

initialize

public void initialize(double xmin,
                       double xmax,
                       int numpts,
                       boolean filled)

Initialize the function range and the number of display points.

Parameters:

xmin - the beginning value of the range.

xmax - the ending value for the range

numpts - the number of points to display

filled - fills the area under the curve with the drawing color when true

getPath

public java.awt.geom.GeneralPath getPath()

Gets the general path that draws this function.

Returns:

GeneralPath

getXRange

public double[] getXRange()

Get the range of x values over which the function has been evaluated.

Returns:

double[2] the xmin and xmax values

getYRange

public double[] getYRange()

Get the minimum and maximum y values for the function.

Returns:

double[2] the ymin and ymax values

checkRange

protected void checkRange(DrawingPanel panel)

draw

public void draw(DrawingPanel panel,
                 java.awt.Graphics g)

Draw the function on a drawing panel.

Specified by:

draw in interface Drawable

Parameters:

panel - the drawing panel

g - the graphics context

setFilled

public void setFilled(boolean _filled)

Fills the area under the curve when true.

Parameters:

_filled - boolean

setColor

public void setColor(java.awt.Color c)

Sets the drawing color.

Parameters:

c - Color

isMeasured

public boolean isMeasured()

Description copied from interface: Measurable

Determines if information is available to set min/max values. Objects that store data should return false if data is null.

Specified by:

isMeasured in interface Measurable

Returns:

true if min/max values are valid

getXMin

public double getXMin()

Description copied from interface: Measurable

Gets the minimum x needed to draw this object.

Specified by:

getXMin in interface Measurable

Returns:

minimum

getXMax

public double getXMax()

Description copied from interface: Measurable

Gets the maximum x needed to draw this object.

Specified by:

getXMax in interface Measurable

Returns:

maximum

getYMin

public double getYMin()

Description copied from interface: Measurable

Gets the minimum y needed to draw this object.

Specified by:

getYMin in interface Measurable

Returns:

minimum

getYMax

public double getYMax()

Description copied from interface: Measurable

Gets the maximum y needed to draw this object.

Specified by:

getYMax in interface Measurable

Returns:

minimum