 Correspondence Analysis Results - Advanced Tab

Select the Advanced tab of the Correspondence Analysis Results dialog box to access the options described here.

Row and column coordinates. Click the Row and column coordinates button to display a spreadsheet with the coordinates for the row and column points, as well as various additional statistics that are useful for evaluating the adequacy of the number of dimensions in the current solution. Also, if you have specified supplementary row and/or column points, then the coordinates for those points, as well as related statistics, will also be included in the spreadsheet. Two spreadsheets will be displayed, one for the row points and one for the column points. See Row and column points in Correspondence Analysis for more details about the statistics given in the spreadsheets.

Print/report summary of results. Click the Print/report summary of results button to send the information shown in the Summary box to a report and to display spreadsheets of the analysis results. If the current Output Manager settings do not specify output to a report when you click the Print/report summary of results button, a dialog box is displayed that gives you the option to modify the Output Manager. Click the Yes button to display the Analysis/Graph Output Manager dialog box, in which you can select an Output Report Window option.

Eigenvalues. Click the Eigenvalues button to display a spreadsheet with the generalized singular values, eigenvalues, and related statistics. Note that the dimensions are "extracted" so as to maximize the distances between the row or column points, and successive dimensions (which are independent of or orthogonal to each other) will "explain" less and less of the overall Chi-square value (and, thus, inertia; refer to Computational details for additional information).

Plot. Click the Plot button to display a line plot of the eigenvalues for the successive dimensions.

Unstandardized matrices. Click the Unstandardized matrices button to display a spreadsheet with the relative frequencies (i.e., the values in the input table, divided by the sum of all values), and the matrices of the left and right generalized singular vectors (see also Computational details). This option is useful if you want to access those matrices via a STATISTICA Visual Basic program, for example, in order to implement a non-standard method of standardizing the row and column coordinates.

Specifically, let the table of relative frequencies be denoted as matrix P. Further, let P = A DuB' denote the generalized singular value decomposition of P. After you click on this option, the three spreadsheets will show matrices P, A, and B (matrix Du is a diagonal matrix, where the diagonal elements are equal to the singular values, which are reported when you select the Eigenvalues button).

Plots of coordinates. Use the options in the Plots of coordinates group box to plot the row and/or column points, along with supplementary points (if any were specified) in 1D plots, 2D plots, or 3D plots. Note that you can use the brushing options to eliminate individual points from the plots (e.g., to leave only points that are clearly spread out along the axes). Also, the orientation of axes is arbitrary, and can, for example, be rotated by 180°. Note that you can quickly achieve this "reversal of scales": right-click on the graph and select Graph Options from the resulting menu to display the dialog box; select the Axis: Scaling tab, and select the Reverse scaling check box.

1D, 2D, 3D plots of row points, column points, and row and column points. If you click on any of these buttons, the respective plots will be produced for all dimensions, pairs of dimensions, or triplets of dimensions currently selected via the options in the Number of dimensions group box (accessible on the Quick tab and Options tab). By default, the points will be labeled with the full row and column names from the table.

Plot selected dimensions only. Select the Plot selected dimensions only check box to plot only the points for selected dimensions, pairs of dimensions, or triplets of dimensions. When this box has been selected, click on any of the buttons to produce graphs to display the Select the dimensions to plot dialog, in which you select the list of dimensions to produce the respective plots.

Truncate labels to chars. Select the Truncate labels to chars check box and enter a value in the corresponding field to display only the specified number of characters of the row and column point names in the graphs. By default the points in the plots will be labeled with the full names for the row and column points. For large tables with many points, the plots may be more readable when you abbreviate the row and column point names.

Use identical X/Y/Z scales. Select the Use identical X/Y/Z scales check box to force all axes in 2D and 3D plots to use identical scaling (minima and maxima) and thus achieve compatibility of scales between dimensions (i.e., axes in the plot). As described in the Introductory Overview, by default (depending on the selected method of Standardization of coordinates, accessed via the Options tab) the distances between the points in the plots are actually Chi-square distances.