edu.hws.jcm.draw

Class RiemannSumRects

java.lang.Object

edu.hws.jcm.draw.Drawable

edu.hws.jcm.draw.RiemannSumRects

All Implemented Interfaces:

Computable, Serializable

public class RiemannSumRects
extends Drawable
implements Computable

A RiemannSumRects calculates a Riemann sum for a function. It implements Computable and InputObject. You can specify and change the number of intervals in the sum, as well as the method used to calculate the sum. Functions exist to return Value objects for the sum using different computations. This class was written by Gabriel Weinstock, with some modifications by David Eck

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	CIRCUMSCRIBED Summation method type.
static int	CURRENT_METHOD For use in getValueObject(), to indicate whatever summation method is currently set for drawing.
static int	INSCRIBED Summation method type.
static int	LEFTENDPOINT Summation method type.
static int	MIDPOINT Summation method type.
static int	RIGHTENDPOINT Summation method type.
static int	TRAPEZOID Summation method type.

Fields inherited from class edu.hws.jcm.draw.Drawable

canvas, coords

Constructor Summary

Constructors

Constructor and Description
RiemannSumRects() Construct a RiemannSumRects object that initially has nothing to draw and that is set up to use the default number of intervals, 5.
RiemannSumRects(Function f, Value i) Construct a new RiemannSumRects object.

Method Summary

Modifier and Type	Method and Description
void	compute() This is generally called by a Controller.
void	draw(Graphics g, boolean coordsChanged) Draw the Rieman sum rects.
Color	getColor() Get the current color used to draw the rectangles
Function	getFuction() Returns the function whose Riemann sums are computed.
Value	getIntervalCount() Get the number of intervals used.
int	getMethod() Return the current method used to find the rectangle sums
Color	getOutlineColor() Get the color that is used to draw outlines around the rects.
Value	getValueObject(int which) Gets a Value object that gives the value of the Riemann sum for the specified method.
void	setColor(Color c) Set the color used to draw the rectangles.
void	setFunction(Function func) Set the function whose Riemann sums are to be computed.
void	setIntervalCount(Value c) Set the interval count (the RiemannSumRects will be redrawn after this function is called).
void	setMethod(int m) Set the method used to calculate the rectangles.
void	setOutlineColor(Color c) Set the color that will be used to draw outlines around the rects.

Methods inherited from class edu.hws.jcm.draw.Drawable

getVisible, needsRedraw, setOwnerData, setVisible

Methods inherited from class java.lang.Object

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

Field Detail

LEFTENDPOINT

public static final int LEFTENDPOINT

Summation method type.

See Also:

Constant Field Values

RIGHTENDPOINT

public static final int RIGHTENDPOINT

Summation method type.

See Also:

Constant Field Values

MIDPOINT

public static final int MIDPOINT

Summation method type.

See Also:

Constant Field Values

CIRCUMSCRIBED

public static final int CIRCUMSCRIBED

Summation method type.

See Also:

Constant Field Values

INSCRIBED

public static final int INSCRIBED

Summation method type.

See Also:

Constant Field Values

TRAPEZOID

public static final int TRAPEZOID

Summation method type.

See Also:

Constant Field Values

CURRENT_METHOD

public static final int CURRENT_METHOD

For use in getValueObject(), to indicate whatever summation method is currently set for drawing.

See Also:

Constant Field Values

Constructor Detail

RiemannSumRects

public RiemannSumRects()

Construct a RiemannSumRects object that initially has nothing to draw and that is set up to use the default number of intervals, 5.

RiemannSumRects

public RiemannSumRects(Function f,
                       Value i)

Construct a new RiemannSumRects object.

Parameters:

i - a Value object representing the number of intervals. If null, five intervals are used.

f - a Function object used to derive the Riemann sum. If null, nothing is drawn.

Method Detail

getColor

public Color getColor()

Get the current color used to draw the rectangles

setColor

public void setColor(Color c)

Set the color used to draw the rectangles. The default color is a light yellow.

setOutlineColor

public void setOutlineColor(Color c)

Set the color that will be used to draw outlines around the rects. If this is null, then no outlines are drawn. The default is a medium-dark red that looks brownish next to the default yellow fill color.

getOutlineColor

public Color getOutlineColor()

Get the color that is used to draw outlines around the rects. If this is null, then no outlines are drawn.

setFunction

public void setFunction(Function func)

Set the function whose Riemann sums are to be computed. If null, nothing is drawn. The function, if non-null, must have arity 1, or an IllegalArgumentException is thrown.

getFuction

public Function getFuction()

Returns the function whose Riemann sums are computed. Can be null.

setMethod

public void setMethod(int m)

Set the method used to calculate the rectangles.

Parameters:

m - can be: LEFTENDPOINT, RIGHTENDPOINT, MIDPOINT, CIRCUMSCRIBED, INSCRIBED or TRAPEZOID (these are integers ranging from 0 to 5, respectively)

getMethod

public int getMethod()

Return the current method used to find the rectangle sums

compute

public void compute()

This is generally called by a Controller. Indicates that all data should be recomputed because input values that the data depends on might have changed.

Specified by:

compute in interface Computable

getIntervalCount

public Value getIntervalCount()

Get the number of intervals used.

Returns:

a Value object representing the number of intervals

setIntervalCount

public void setIntervalCount(Value c)

Set the interval count (the RiemannSumRects will be redrawn after this function is called). The value will be clamped to be a value between 1 and 5000. If the value is null, the default number of intervals, five, is used.

Parameters:

c - a Value object representing the interval count

draw

public void draw(Graphics g,
                 boolean coordsChanged)

Draw the Rieman sum rects. This is generally called by an object of class CoordinateRect

Specified by:

draw in class Drawable

Parameters:

g - The graphics context in which the Drawble is to be drawn. (The drawing can change the color in g, but should not permanently change font, painting mode, etc. Thus, every drawable is responsible for setting the color it wants to use.)

coordsChanged - Indicates whether the CoordinateRect has changed.

getValueObject

public Value getValueObject(int which)

Gets a Value object that gives the value of the Riemann sum for the specified method.

Parameters:

which - integer stating the method used to derive the sum; one of the constants LEFTENDPOINT, RIGHTENDPOINT, MIDPOINT, CIRCUMSCRIBED, INSCRIBED, TRAPEZOID, or CURRENT_METHOD.

Returns:

a Value object representing the sum for the given method