magpie.attributes.selectors

Class RemoveCorrelatedAttributeSelector

java.lang.Object

magpie.attributes.selectors.BaseAttributeSelector

magpie.attributes.selectors.RemoveCorrelatedAttributeSelector

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Commandable, Options, Printable

public class RemoveCorrelatedAttributeSelector
extends BaseAttributeSelector

Finds pairs of attributes that are correlated with each other, and removes one of the two. User can specify which correlation measure they use, and whether to pick the attribute that correlates best with the class variable. The threshold defines the minimum absolute value of the correlation coefficient at which attributes are marked as "correlated."

Usage: [<-useclass>] <-pearson|-spearman|-kendall> <threshold>
-useclass: Whether to pick the attribute that correlates best with the class variable
-pearson: Use Pearson's correlation coefficient
-spearman: Use Spearman's correlation coefficient
-kendall: Use Kendall's correlation coefficient
threshold: Mark entries as correlated if coefficient greater than this value

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RemoveCorrelatedAttributeSelector.CorrelationMeasure List of correlation measures

Field Summary

Fields

Modifier and Type	Field and Description
protected RemoveCorrelatedAttributeSelector.CorrelationMeasure	Measure Correlation measure used for this class
protected double	Threshold Threshold at which attributes are marked as correlated.
protected boolean	UseClass Whether to pick the attribute most strongly correlated with the class variable

Fields inherited from class magpie.attributes.selectors.BaseAttributeSelector

trained

Constructor Summary

Constructors

Constructor and Description
RemoveCorrelatedAttributeSelector()

Method Summary

Modifier and Type	Method and Description
protected double	measureCorrelation(double[] x, double[] y) Measure the strength correlation between two arrays
java.lang.String	printDescription(boolean htmlFormat) Print full name of object, and a simple description of the options.
java.lang.String	printUsage() Print out required format for options.
void	setMeasure(RemoveCorrelatedAttributeSelector.CorrelationMeasure measure) Define the method used to measure correlation
void	setOptions(java.util.List<java.lang.Object> Options) Set any options for this object.
void	setThreshold(double threshold) Define the threshold at which attributes are declared "correlated"
void	setUseClass(boolean useClass) Define whether to select the attribute most correlated with the class variable when selecting which pair of correlated attributes to keep.
protected java.util.List<java.lang.Integer>	train_protected(Dataset Data) Operation that actually does the work for training.

Methods inherited from class magpie.attributes.selectors.BaseAttributeSelector

about, applyAttributeSelection, clone, getSelectionNames, getSelections, isTrained, printCommand, printSelections, run, runCommand, train

Methods inherited from class java.lang.Object

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

Field Detail

Measure

protected RemoveCorrelatedAttributeSelector.CorrelationMeasure Measure

Correlation measure used for this class

Threshold

protected double Threshold

Threshold at which attributes are marked as correlated.

UseClass

protected boolean UseClass

Whether to pick the attribute most strongly correlated with the class variable

Constructor Detail

RemoveCorrelatedAttributeSelector

public RemoveCorrelatedAttributeSelector()

Method Detail

setOptions

public void setOptions(java.util.List<java.lang.Object> Options)
                throws java.lang.Exception

Description copied from interface: Options

Set any options for this object. If parsing the options fails, return an Exception with the usage as its message.

Parameters:

Options - Array of options as Objects - can be null

Throws:

java.lang.Exception - if problem with inputs

printUsage

public java.lang.String printUsage()

Description copied from interface: Options

Print out required format for options. For consistency, should start with "Usage: ".

Returns:

Usage for this function

setMeasure

public void setMeasure(RemoveCorrelatedAttributeSelector.CorrelationMeasure measure)

Define the method used to measure correlation

Parameters:

measure - Desired method

setUseClass

public void setUseClass(boolean useClass)

Define whether to select the attribute most correlated with the class variable when selecting which pair of correlated attributes to keep.

Parameters:

useClass - Desired setting

setThreshold

public void setThreshold(double threshold)

Define the threshold at which attributes are declared "correlated"

Parameters:

threshold - Correlation coefficient

train_protected

protected java.util.List<java.lang.Integer> train_protected(Dataset Data)

Description copied from class: BaseAttributeSelector

Operation that actually does the work for training. Must generate a list of attribute IDs

Specified by:

train_protected in class BaseAttributeSelector

Parameters:

Data - Dataset used to train selector

Returns:

List of indexes of selected attributes

measureCorrelation

protected double measureCorrelation(double[] x,
                                    double[] y)

Measure the strength correlation between two arrays

Parameters:

x - One array

y - A second array

Returns:

The magnitude of the correlation coefficient between these two arrays

printDescription

public java.lang.String printDescription(boolean htmlFormat)

Description copied from interface: Printable

Print full name of object, and a simple description of the options. This description should print enough information to reproduce how this object was created, but not necessarily enough to run it (e.g., coefficients for the model).

Example: For a model training a separate WekaRegression for intermetallics

magpie.models.regression.SplitRegression

Splitter: AllMetalsSplitter
All Metals: magpie.models.regression.WekaRegression trees.REPTree
Contains Nonmetal: magpie.regression.LASSORegreession -maxterms 2

Specified by:

printDescription in interface Printable

Overrides:

printDescription in class BaseAttributeSelector

Parameters:

htmlFormat - Whether format for output to an HTML page (e.g., <div> to create indentation) or for printing to screen.

Returns:

String describing the model

See Also:

#printModel()