Modeling and Multivariate Methods - SAS

Chapter 17 Correlations and Multivariate Techniques 451
Multivariate Platform Options
Table 17.2 Options for the Scatterplot Matrix (Continued)
Shaded Ellipses
Show Correlations
Show Histogram
Ellipse α
Ellipses Transparency
Ellipse Color
Colors each ellipse. Use the Ellipses Transparency and Ellipse Color
menus to change the transparency and color.
Shows or hides the correlation of each histogram in the upper left corner of
each scatterplot.
Shows either horizontal or vertical histograms in the label cells. Once
histograms have been added, select Show Counts to label each bar of the
histogram with its count. Select Horizontal or Vertical to either change the
orientation of the histograms or remove the histograms.
Sets the α-level used for the ellipses. Select one of the standard α-levels in
the menu, or select Other to enter a different one. The default value is
0.95.
Sets the transparency of the ellipses if they are colored. Select one of the
default levels, or select Other to enter a different one. The default value is
0.2.
Sets the color of the ellipses if they are colored. Select one of the colors in
the palette, or select Other to use another color. The default value is red.
Outlier Analysis
The Outlier Analysis menu contains options that show or hide plots that measure distance in the
multivariate sense using one of these methods:
• Mahalanobis distance
• jackknife distances
• T 2 statistic
These methods all measure distance in the multivariate sense, with respect to the correlation structure).
In Figure 17.4, Point A is an outlier because it is outside the correlation structure rather than because it is an
outlier in any of the coordinate directions.