com.itemanalysis.psychometrics.factoranalysis

Interface FactorMethod

All Known Implementing Classes:

AbstractFactorMethod, GeneralizedLeastSquaresMethod, MaximumLikelihoodMethod, MINRESmethod, PrincipalComponentsMethod, WeightedLeastSquaresMethod

public interface FactorMethod

This interface allows for a variety of methods for estimating parameters in exploratory factor analysis.

Method Summary

Modifier and Type	Method and Description
double	estimateParameters() A method for estimating parameters.
double	getCommunalityAt(int i) Returns the communality (sum of squared factor laodings) for a variable.
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	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.
VariableName	getVariableNameAt(int index) Returns the name of the variable at index.
void	setVariableNameAt(int index, VariableName name)

Method Detail

estimateParameters

double estimateParameters()

A method for estimating parameters. The returned value is the value of the criterion function at the estimated values. It should be the smallest possible value. This value is returned for display in the output.

Returns:

value of the criterion function at the estimated values

getFactorLoadingAt

double getFactorLoadingAt(int i,
                          int j)

Return a factor loading for a particular item.

Parameters:

i - variable index of the factor loading

j - factor index of the loading

Returns:

getLoadingsForFactorAt

double[] getLoadingsForFactorAt(int factorID)

Returns all factor loadings for a particular factor

Parameters:

factorID - position number of factor of interest.

Returns:

array of factor loadings.

getUniquenessAt

double getUniquenessAt(int i)

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

Parameters:

i - variable index of the uniqueness

Returns:

getCommunalityAt

double getCommunalityAt(int i)

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

Parameters:

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

Returns:

communality for a variable.

getSumsOfSquaresAt

double getSumsOfSquaresAt(int j)

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

Parameters:

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

Returns:

sum of squared factor loadings.

getProportionOfExplainedVarianceAt

double getProportionOfExplainedVarianceAt(int j)

Proportion of explained variance

Parameters:

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

Returns:

getProportionOfVarianceAt

double getProportionOfVarianceAt(int j)

Returns the proportion of total variance for a factor.

Parameters:

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

Returns:

getVariableNameAt

VariableName getVariableNameAt(int index)

Returns the name of the variable at index.

Parameters:

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

Returns:

variable name.

setVariableNameAt

void setVariableNameAt(int index,
                       VariableName name)