com.itemanalysis.psychometrics.factoranalysis

Class AbstractFactorMethod

java.lang.Object

com.itemanalysis.psychometrics.factoranalysis.AbstractFactorMethod

All Implemented Interfaces:

FactorMethod

Direct Known Subclasses:

GeneralizedLeastSquaresMethod, MaximumLikelihoodMethod, MINRESmethod, PrincipalComponentsMethod, WeightedLeastSquaresMethod

public abstract class AbstractFactorMethod
extends java.lang.Object
implements FactorMethod

An abstract implementation of FactorMethod. It includes methods that are common to all specific instances of FactorMethod. See the FactorMethod interface for details on each of the methods below.

Field Summary

Fields

Modifier and Type	Field and Description
protected double[]	communality
protected double[][]	factorLoading
protected int	nFactors
protected int	nParam
protected int	nVariables
protected double[]	proportionOfExplainedVariance
protected double[]	proportionOfVariance
protected org.apache.commons.math3.linear.RealMatrix	R
protected RotationMethod	rotationMethod
protected double[]	sumsOfSquares
protected double[]	uniqueness
protected VariableName[]	variableNames

Constructor Summary

Constructors

Constructor and Description
AbstractFactorMethod()

Method Summary

Modifier and Type	Method and Description
double	getCommunalityAt(int i) Returns the communality (sum of squared factor laodings) for a variable.
double[][]	getFactorLoading()
double	getFactorLoadingAt(int i, int j) Return a factor loading for a particular item.
double[]	getLoadingsForFactorAt(int factorID) Returns all factor loadings for a particular factor
double[]	getLowerBounds() Lower bounds of the parameters
double	getProportionOfExplainedVarianceAt(int j) Proportion of explained variance
double	getProportionOfVarianceAt(int j) Returns the proportion of total variance for a factor.
double	getSumsOfSquaresAt(int j) Sum of squared factor loading for a particular factor.
double	getUniquenessAt(int i) Returns the variabl's uniqueness (i.e.
double[]	getUpperBounds() Upper bound of the parameters
VariableName	getVariableNameAt(int index) Returns the name of the variable at index.
void	setVariableNameAt(int index, java.lang.String name)
void	setVariableNameAt(int index, VariableName name)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.itemanalysis.psychometrics.factoranalysis.FactorMethod

estimateParameters

Field Detail

R

protected org.apache.commons.math3.linear.RealMatrix R

nVariables

protected int nVariables

nFactors

protected int nFactors

nParam

protected int nParam

rotationMethod

protected RotationMethod rotationMethod

factorLoading

protected double[][] factorLoading

uniqueness

protected double[] uniqueness

communality

protected double[] communality

sumsOfSquares

protected double[] sumsOfSquares

proportionOfVariance

protected double[] proportionOfVariance

proportionOfExplainedVariance

protected double[] proportionOfExplainedVariance

variableNames

protected VariableName[] variableNames

Constructor Detail

AbstractFactorMethod

public AbstractFactorMethod()

Method Detail

getLowerBounds

public double[] getLowerBounds()

Lower bounds of the parameters

Returns:

getUpperBounds

public double[] getUpperBounds()

Upper bound of the parameters

Returns:

getFactorLoading

public double[][] getFactorLoading()

getFactorLoadingAt

public double getFactorLoadingAt(int i,
                                 int j)

Description copied from interface: FactorMethod

Return a factor loading for a particular item.

Specified by:

getFactorLoadingAt in interface FactorMethod

Parameters:

i - variable index of the factor loading

j - factor index of the loading

Returns:

getLoadingsForFactorAt

public double[] getLoadingsForFactorAt(int factorID)

Description copied from interface: FactorMethod

Returns all factor loadings for a particular factor

Specified by:

getLoadingsForFactorAt in interface FactorMethod

Parameters:

factorID - position number of factor of interest.

Returns:

array of factor loadings

getUniquenessAt

public double getUniquenessAt(int i)

Description copied from interface: FactorMethod

Returns the variabl's uniqueness (i.e. residual value)

Specified by:

getUniquenessAt in interface FactorMethod

Parameters:

i - variable index of the uniqueness

Returns:

getCommunalityAt

public double getCommunalityAt(int i)

Description copied from interface: FactorMethod

Returns the communality (sum of squared factor laodings) for a variable. The sum is computed over factors.

Specified by:

getCommunalityAt in interface FactorMethod

Parameters:

i - index of the variable for which the communality is sought.

Returns:

communality for a variable.

getSumsOfSquaresAt

public double getSumsOfSquaresAt(int j)

Description copied from interface: FactorMethod

Sum of squared factor loading for a particular factor. The sum is computed over items.

Specified by:

getSumsOfSquaresAt in interface FactorMethod

Parameters:

j - index of the factor for which the computation is needed.

Returns:

sum of squared factor loadings.

getProportionOfExplainedVarianceAt

public double getProportionOfExplainedVarianceAt(int j)

Description copied from interface: FactorMethod

Proportion of explained variance

Specified by:

getProportionOfExplainedVarianceAt in interface FactorMethod

Parameters:

j - index of the factor for which the explained variance is computed

Returns:

getProportionOfVarianceAt

public double getProportionOfVarianceAt(int j)

Description copied from interface: FactorMethod

Returns the proportion of total variance for a factor.

Specified by:

getProportionOfVarianceAt in interface FactorMethod

Parameters:

j - ndex of the factor for which the proportion of variance is computed

Returns:

getVariableNameAt

public VariableName getVariableNameAt(int index)

Description copied from interface: FactorMethod

Returns the name of the variable at index.

Specified by:

getVariableNameAt in interface FactorMethod

Parameters:

index - position (zero based) of variable for which name is sought.

Returns:

variable name.

setVariableNameAt

public void setVariableNameAt(int index,
                              VariableName name)

Specified by:

setVariableNameAt in interface FactorMethod

setVariableNameAt

public void setVariableNameAt(int index,
                              java.lang.String name)