Principal Components Analysis - Graphs
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Stat > Multivariate > Principal Components> Graphs

Displays plots for judging the importance of the different principal components, examining the scores of the first two principal components, and identifying outliers.

Dialog box items

Scree plot: Check to display a Scree plot (eigenvalue profile plot). Minitab plots the eigenvalue associated with a principal component versus the number of the component. Use this plot to judge the relative magnitude of eigenvalues.

Score plot for first 2 components: Check to plot the scores for the second principal component (y-axis) versus the scores for the first principal component (x-axis). To create plots for other components, store the scores and use Graph > Scatterplot.

Loading plot for first 2 components: Check to plot the loadings for the second component (y-axis) versus the loadings for the first component (x-axis). A line is drawn from each loading to the (0, 0) point.

Biplot for first 2 components: Check to plot an overlay of the score and loading plots for the first two components.

Outlier plot: Check to plot the Mahalanobis distance for each data point. Use this plot to identify outliers in multivariate space. A point above the Y reference line represents an unusual observation.