The Plots Tab

You can use the Plots tab (Figure 26.4) to create plots that graphically display results of the analysis.

Creating a plot often adds one or more variables to the data table. The following plots are available:

Proportion plot of eigenvalues (scree plot)

creates a plot that summarizes the eigenvalues of the correlation or covariance matrix.

Show cumulative proportions

adds cumulative proportions of eigenvalues to the proportion plot.

Matrix of component score plots

creates a matrix of scatter plots showing scores for consecutive pairs of principal components.

Correlation pattern plot

creates a line plot that shows the correlations between principal components and the original variables.

Biplot

creates a biplot. A biplot shows relationships between observations and variables in a single plot.

Scale factors

specifies how to scale and factor the SVD of the data matrix. The scaling determines the values for the biplot. The methods are described in the section "Biplots".

Extend variable vectors

specifies whether to extend the vectors to the edge of the biplot. This is useful for visualizing the direction of short vectors.