Product-Moment and Partial Correlations - Advanced Tab

Select the Advanced tab of the Product-Moment and Partial Correlations dialog box to access options to review a variety of correlations, partial correlations, and plots for the selected variables.

Summary: Correlation matrix. Click this button to produce a spreadsheet containing the correlation matrix for the currently selected variables (via the Product-Moment and Partial Correlations dialog box). The computation of correlations and the display format depends on the settings on the Options tab.

Graphs. Click the Graphs button to create scatterplots with histograms and associated descriptive statistics for the selected variables.

Matrix 1. Click this button to create a new square correlation matrix spreadsheet (i.e., correlations for variables specified via the One variable list option). Note that this button is not available when variables have been specified using two lists. The matrix spreadsheet that is created is always in a stand-alone windows (regardless of the settings in the Analysis Output Manager) with four additional cases at the bottom of the data file that identify it as a matrix spreadsheet (see Matrix file format). You can, however, add the spreadsheet to a workbook or report using the Add to Workbook or Add to Report buttons on the Home tab. In order to save the matrix spreadsheet, select the matrix and select Save or Save As on the File tab. Statistica then detects that the spreadsheet is in this special matrix form, and sets the default file extension to .smx. This makes it easier to distinguish the file later.

Partial correlations. Click this button to produce a spreadsheet containing the partial correlations matrix. Partial correlations are computed for the variables in the first list, controlling for the variables in the second list. Note that if you haven't already specified variables using the Two lists (rect. matrix) option, a two-variable list selection dialog box is displayed.

Matrix 2. Click this button to create a partial correlation matrix spreadsheet. The matrix spreadsheet is always in a stand-alone windows (regardless of the settings in the Analysis Output Manager) with four additional cases at the bottom of the data file that identify it as a matrix spreadsheet (see Matrix file format). You can, however, add the spreadsheet to a workbook or report using the Add to Workbook or Add to Report buttons on the Home tab. In order to save the matrix spreadsheet, select the matrix and select Save or Save As on the File tab. Statistica then detects that the spreadsheet is in this special matrix form, and sets the default file extension to .smx. This makes it easier to distinguish the file later.

2D scatterplots / with casenames. Click either the 2D scatterplot or the with casenames button to produce a cascade of scatterplots for selected pairs of Variables. A variable selection dialog box is displayed in which you select the variable(s) for the x- and y-axes; one plot is produced per variable pair. When the 2D scatterplots button is used, the plot shows the regression line and the standard error of the predicted values (as error lines) in the scatterplot. When the with casenames button is used, the scatterplot does not contain those lines, but identifies the points in the scatterplot with the case numbers or names (if case names are specified in the respective data file).

3D scatterplots / with casenames. Click either the 3D scatterplots or the with casenames button to produce a 3D scatterplot for a selected triplet of variables. A variable selection dialog box is displayed in which you select the variable for the x-, y-, and z-axes. When the with casenames button is used, the points in the scatterplot are identified by the case numbers or names (if case names are specified in the respective data file).

Scatterplot matrix. Click this button to produce a scatterplot matrix for selected variables. A variable selection dialog box is displayed in which you select the variables for the plot.

Categorized scatterplot. Click this button to produce a cascade of categorized scatterplots for selected pairs of variables, one plot per pair. You are first prompted via a variable selection dialog box to select two lists of variables (from among those originally selected via the Variable list buttons). Scatterplots are produced for each variable in the first list with each variable in the second list. Next (via another variable selection dialog box) you are prompted to select up to two categorical variables. Then, the Select Codes for the Grouping Variables dialog box is displayed in which you specify the specific groups of each of your categorical variables for which you want graphs to be produced. Finally, Statistica produces a cascade of scatterplots broken down (categorized) by the specified groups in the categorical variables. Note that more complex breakdown analyses and graphs are available via the Breakdown & one-way ANOVA option on the Basic Statistics and Tables dialog box - Quick tab.

Surface plots. Click this button to produce a 3D scatterplot for a selected triplet of variables, and fit a quadratic surface to the data. A variable selection dialog box is displayed in which you select the variables for the plot.

3D histograms. Click this button to produce a cascade of 3D histograms for selected pairs of variables, one plot per pair. If a single list of variables was previously selected (via the One variable list option), a variable selection dialog box is displayed in which you select two lists of variables from among the previously selected variables, and 3D histograms are produced for each variable in the first list with each variable in the second list. If two lists of variables were previously selected (via the Two lists (rect. matrix) option), 3D histograms are automatically produced for each variable in the first list with each variable in the second list

See also, Exploratory Data Analysis (EDA) and Data Mining Techniques.