Joining Results - Advanced Tab

Joining (Tree Clustering)

Select the Advanced tab in the Joining Results dialog box to access the options described here.

Horizontal hierarchical tree plot. Click this button to display a horizontal tree diagram summarizing the successive clustering of objects. Refer to Joining (Tree Clustering) Introductory Overview - hierarchical tree for a brief discussion of how to interpret the tree diagram.

Vertical icicle plot. Click this button to display a vertical tree diagram (the vertical axis denotes the linkage distance). Refer to the Joining (Tree Clustering) Introductory Overview - hierarchical tree for a brief discussion of how to interpret the tree diagram.

Rectangular branches. Select this check box to display either type of tree plot (see above) with rectangular branches. Clear this check box to display the tree plot with diagonal branches, which may increase readability of the diagram for solutions with "balanced" joining structures.

Scale tree to dlink/dmax*100. Select this check box in order for the tree plot to be scaled to a standardized scale (i.e., dlink/dmax*100). If the check box is cleared, the scale will be based on the linkage distance selected on the Cluster Analysis: Joining (Tree Clustering) dialog box - Advanced tab.

Note: Depending on the current default scale value font-size setting (see Axis: scale values), the item (case or variable) labels in the tree plot may overlap or the display of some (e.g., every other or third) overlapping labels may be suppressed; in such cases, click on the labels in the graph and reduce the font size.

Amalgamation schedule. Click this button to display a spreadsheet with the amalgamation (linkage) schedule. The first column of the spreadsheet contains the linkage distances at which the respective clusters (as indicated in the respective rows) were formed, and each row contains the names of the objects (cases or variables) that comprise the respective cluster.

Graph of amalgamation schedule. Click this button to display a line graph of the linkage distances across consecutive steps of the linking process. This graph is useful for identifying plateaus where many clusters are formed at approximately the same linkage distance. This may indicate a natural "discontinuity" in terms of distances between the observed objects.

Distance matrix. Click the Distance matrix button to display a standard spreadsheet containing the matrix of distances.

Descriptive statistics. Click this button to display a standard spreadsheet containing means and standard deviations for each object included in the cluster analysis (i.e., for each case or variable, depending on the selection made in the Cluster box in the Cluster Analysis: Joining (Tree Clustering) dialog box).

Matrix. Click this button to create a matrix spreadsheet of the current distance matrix. The matrix spreadsheet (shown in an individual window regardless of the settings in the Options dialog box - Output Manager tab or the Analysis/Graph Output Manager dialog box) contains four additional cases at the bottom of the data file, which identify it as a matrix spreadsheet (see Matrix file format). To save the matrix spreadsheet, select the matrix and use the File menu Save or Save As options. STATISTICA detects that the spreadsheet is in this special matrix form and sets the default file extension to .smx. You also can add the spreadsheet to a workbook or report using the or buttons, respectively.

Save classifications. Click this button to display a tree diagram. You can click and drag the red reference line along the x-axis in the tree diagram to indicate the cutoff that defines the cluster memberships. Once you have made your cutoff selection, click OK in the Brushing box. A variable selection dialog box is then displayed so that you can select input variables from the spreadsheet to be included in the spreadsheet of cluster memberships. After making your variable selections, click OK. If you choose not to copy any variables into the results spreadsheet, click Cancel.

Sort by cluster membership. Select this check box to display the results for sorted by (assigned) cluster rather than case number.