Graphics Reference
In-Depth Information
Display of Scatterplot Matrix
6.3.2
Figure
.
has several noteworthy characteristics. he panels are symmetric about
the main diagonal running from SW to NE, which, as explained below, is a more
appealing choice than NW to SE. he panels are square, which makes sense because
both dimensions contain the same variables. We display both y
y since
we don't know in advance which is more helpful or appropriate. he panels on the
main diagonal are used for labeling and tick marks.
Figure
.
contains an alternate splom orientation that we do not recommend. In
the alternate orientation, with the downhill diagonal and rectangular panels, each
variable is depicted on two different scales, making comparisons of each panel with
its transpose more di
cult than with an uphill diagonal and square panels.
Figure
.
compares the axes of symmetry of figures resembling Figs.
.
and
.
.
Figure
.
ahassixaxesofsymmetry.Wefocusonpanel
,whichappearsinpositions
reflected about the main NW-SE axis. he individual points within panels
and
′
are reflected about the dashed SW-NEline, as indicated bythe position of the arrow.
he other four axes, which reflect respectively panel
, panels
and
, panel
, and
panel
, are indicated with dotted lines. Figure
.
b has only one axis of symmetry.
he arrow for panel
is reflected by the same SW-NE axis that reflects panels
and
′
.
x and x
Figure
.
.
log(televisions), log(physicians), and life expectancy (File: hh/grap/code/grap.f
.s)
