FactanalGUI {DASplusR}R Documentation

GUI for Factor Analysis

Description

Graphical user interface for factor analysis. The function factanalDAS is executed when the OK button is clicked and the results are summarized in the output window of DAS+R.

Usage

## DAS+R GUI: 
Advanced --> Factor Analysis --> Compute Factors

## R Function Usage:
FactanalGUI()

Dialog Elements

Select Variables:
In case there are at least three variables preselected in DAS+R, only these are shown in the listbox. Otherwise, it contains all numerical variables of the active data set. Use the radiobuttons on the right to select or deselect all variables.
Log-Transformation:
If this checkbox is checked, a dialog for selecting the variables to be log-transformed is opened when the OK button is clicked.
Number of Factors:
Enter the number of factors to be fitted in FA. If it is set to 1, the checkbox for the biplot is disabled, since there are two factors required for a biplot.
Previously Calculated Factors:
By checking this checkbox, a previously calculated object of class "factanal" can be selected from the drop-down list on the right. For such an object, the function call that has been used for its computation is stored. The object is only shown in this list if one of the following conditions on the function call holds: either the active data set has been used as the data argument, or no data argument has been supplied. When using this option, all other dialog elements, except the checkboxes for the factor loading plot and the biplot, are disabled because no calculation will be done. They can be used again when this checkbox is unchecked.
Robust Covariance Matrix Estimation:
Check this checkbox for using a robust estimation method for the covariance matrix. MCD or OGK estimation can be chosen from the drop-down list. Also, the checkbox for using a previously calculated covariance matrix is disabled and cannot be used until this checkbox is unchecked again.
Previously Calculated Covariance Matrix:
Checking this checkbox allows the selection of a previously calculated covariance matrix to be used in FA. The drop-down list contains all matrices and covariance lists, i.e., lists that contain elements named center and cov, as returned by cov.wt (or covMcd from package robustbase). Since scores can only be computed if an estimate of the central location of the data is supplied, this is not possible if the selected object is a matrix. In any case, make sure that the selected variables are the same that have been used to calculate the covariance matrix. Also, the dialog elements for log-transformation and robust estimation of the covariance matrix are disabled until this box is unchecked again, because these options cannot be used with a previously calculated covariance matrix.
Factor Rotation:
By checking this checkbox, a rotation method to be applied to the factors can be selected. Possible choices from the drop-down list are Varimax and Promax factor rotation.
Scores Type:
The type of scores to be computed can be selected from this drop-down list. Select Regression for Thomson's regression scores and Bartlett for Bartlett's weighted least-squares scores.
Plots:
Check the checkboxes for the factor loading plot and/or the biplot to produce the respective plots. When the OK button is clicked, the corresponding dialogs are called.
Name for the Object to be Returned:
The combo box can be used to enter a name, or to select the name of an already existing object. Keep in mind that an existing object will be overwritten without asking for confirmation. The drop-down list contains objects of class "factanal". Which objects are included depends on the function calls used for their computation. One of the following two conditions has to hold: either the active data set has been used as the data argument, or no data argument has been supplied.
Default:
Resets all the dialog elements to their default values.
OK:
Closes the dialog and executes factanalDAS. A summary of the results is shown in the output window of DAS+R.
Cancel:
Closes the dialog without executing factanalDAS.
Help:
Shows this help file.

Note

The correlation matrix is always used to compute the factors. Therefore, constant variables cannot be included in FA.

Author(s)

Andreas Alfons <andreas.alfons@student.tuwien.ac.at>

References

Bartlett, M. S. (1937) The statistical conception of mental factors. British Journal of Psychology, 28, 97–104.

Lawley, D.N. and Maxwell, A.E. (1971) Factor Analysis as a Statistical Method, 2nd edition. Butterworths.

Mardia, K.V., Kent, J.T. and Bibby, J.M. (1979) Multivariate Analysis. Academic Press.

Johnson, R.A. and Wichern, D.W. (2002) Applied Multivariate Statistical Analysis. Prentice Hall. 5th edition.

Reimann, C., Filzmoser, P., Garrett, R.G. and Dutter, R. (2008) Statistical Data Analysis Explained. Wiley & Sons.

See Also

factanalDAS, LogTransform, FactplotGUI, BiplotGUI.


[Package DASplusR version 0.0-2 Index]