de.lmu.ifi.dbs.elki.math.geometry

Class XYCurve

java.lang.Object

de.lmu.ifi.dbs.elki.math.geometry.XYCurve

All Implemented Interfaces:

Result, TextWriteable

Direct Known Subclasses:

KNNDistancesSampler.KNNDistanceOrderResult, OutlierPrecisionAtKCurve.PrecisionAtKCurve, OutlierPrecisionRecallCurve.PRCurve, OutlierROCCurve.ROCResult, OutlierSmROCCurve.SmROCResult

public class XYCurve
extends Object
implements Result, TextWriteable

An XYCurve is an ordered collection of 2d points, meant for chart generation. Of key interest is the method addAndSimplify(double, double) which tries to simplify the curve while adding points.

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	XYCurve.Itr Iterator for the curve. 2D, does not follow Java collections style.

Field Summary

Fields

Modifier and Type	Field and Description
protected DoubleArray	data X and Y positions
protected String	labelx Label of X axis
protected String	labely Label of Y axis
protected double	maxx Minimum and maximum for X axis
protected double	maxy Minimum and maximum for Y axis
protected double	minx Minimum and maximum for X axis
protected double	miny Minimum and maximum for Y axis
protected static double	THRESHOLD Simplification threshold

Constructor Summary

Constructors

Constructor and Description
XYCurve() Constructor.
XYCurve(int size) Constructor with size estimate
XYCurve(String labelx, String labely) Constructor with labels
XYCurve(String labelx, String labely, int size) Constructor with size estimate and labels.
XYCurve(XYCurve curve) Constructor, cloning an existing curve.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(double x, double y) Add a coordinate pair, but don't simplify
void	addAndSimplify(double x, double y) Add a coordinate pair, performing curve simplification if possible.
static double	areaUnderCurve(XYCurve curve) Compute the area under curve for a curve monotonously increasing in X.
String	getLabelx() Get label of x axis
String	getLabely() Get label of y axis
String	getLongName() A "pretty" name for the result, for use in titles, captions and menus.
double	getMaxx() Maximum on x axis.
double	getMaxy() Maximum on y axis.
double	getMinx() Minimum on x axis.
double	getMiny() Minimum on y axis.
String	getShortName() A short name for the result, useful for file names.
double	getX(int off) Curve X value at given position
double	getY(int off) Curve Y value at given position
XYCurve.Itr	iterator() Get an iterator for the curve.
void	rescale(double sx, double sy) Rescale the graph.
int	size() Size of curve.
String	toString()
void	writeToText(TextWriterStream out, String label) Write self to the given TextWriterStream

Methods inherited from class java.lang.Object

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

Field Detail

THRESHOLD

protected static final double THRESHOLD

Simplification threshold

See Also:

Constant Field Values

data

protected DoubleArray data

X and Y positions

labelx

protected String labelx

Label of X axis

labely

protected String labely

Label of Y axis

minx

protected double minx

Minimum and maximum for X axis

maxx

protected double maxx

Minimum and maximum for X axis

miny

protected double miny

Minimum and maximum for Y axis

maxy

protected double maxy

Minimum and maximum for Y axis

Constructor Detail

XYCurve

public XYCurve(String labelx,
       String labely)

Constructor with labels

Parameters:

labelx - Label for X axis

labely - Label for Y axis

XYCurve

public XYCurve(String labelx,
       String labely,
       int size)

Constructor with size estimate and labels.

Parameters:

labelx - Label for X axis

labely - Label for Y axis

size - Estimated size (initial allocation size)

XYCurve

public XYCurve()

Constructor.

XYCurve

public XYCurve(int size)

Constructor with size estimate

Parameters:

size - Estimated size (initial allocation size)

XYCurve

public XYCurve(XYCurve curve)

Constructor, cloning an existing curve.

Parameters:

curve - Curve to clone.

Method Detail

add

public void add(double x,
       double y)

Add a coordinate pair, but don't simplify

Parameters:

x - X coordinate

y - Y coordinate

addAndSimplify

public void addAndSimplify(double x,
                  double y)

Add a coordinate pair, performing curve simplification if possible.

Parameters:

x - X coordinate

y - Y coordinate

getLabelx

public String getLabelx()

Get label of x axis

Returns:

label of x axis

getLabely

public String getLabely()

Get label of y axis

Returns:

label of y axis

getMinx

public double getMinx()

Minimum on x axis.

Returns:

Minimum on X

getMaxx

public double getMaxx()

Maximum on x axis.

Returns:

Maximum on X

getMiny

public double getMiny()

Minimum on y axis.

Returns:

Minimum on Y

getMaxy

public double getMaxy()

Maximum on y axis.

Returns:

Maximum on Y

getX

public double getX(int off)

Curve X value at given position

Parameters:

off - Offset

Returns:

X value

getY

public double getY(int off)

Curve Y value at given position

Parameters:

off - Offset

Returns:

Y value

rescale

public void rescale(double sx,
           double sy)

Rescale the graph.

Parameters:

sx - Scaling factor for X axis

sy - Scaling factor for Y axis

size

public int size()

Size of curve.

Returns:

curve length

iterator

public XYCurve.Itr iterator()

Get an iterator for the curve. Note: this is not a Java style iterator, since the only way to get positions is using "next" in Java style. Here, we can have two getters for current values! Instead, use this style of iteration:

 for (XYCurve.Itr it = curve.iterator(); it.valid(); it.advance()) {
   doSomethingWith(it.getX(), it.getY());
 }
 
 

Returns:

Iterator

writeToText

public void writeToText(TextWriterStream out,
               String label)

Description copied from interface: TextWriteable

Write self to the given TextWriterStream

Specified by:

writeToText in interface TextWriteable

Parameters:

out - Output writer

label - Label

toString

public String toString()

Overrides:

toString in class Object

getLongName

public String getLongName()

Description copied from interface: Result

A "pretty" name for the result, for use in titles, captions and menus.

Specified by:

getLongName in interface Result

Returns:

result name

getShortName

public String getShortName()

Description copied from interface: Result

A short name for the result, useful for file names.

Specified by:

getShortName in interface Result

Returns:

result name

areaUnderCurve

public static double areaUnderCurve(XYCurve curve)

Compute the area under curve for a curve monotonously increasing in X. You might need to relate this to the total area of the chart.

Parameters:

curve - Curve

Returns:

Area under curve.