Graphics Reference
In-Depth Information
rectangle r
i
−
into c
i
pieces, where the widths (heights) are proportional to the
breakdown, and keep the height (width) of each the same as r
i
−
.Callthesenew
rectangles r
j
i
,withj
=
,...,c
i
.
. Increase i by
.
. While i
p, repeat steps
and
for all r
i
−
with j
,...,c
i
−
.
Obviously, the hierarchical construction of mosaicplots places a lot of emphasis on
the order of the variables in the plot. As is the case for multiway contingency tables,
different variable orders in mosaics emphasize different aspects of the data; in con-
trastwithtwo-waytables, theorderinwhichthevariables shouldoccurinamultiway
table is not immediately apparent. Tables
.
and
.
show two different arrange-
ments for the same variables of the Titanic data. Each table contains the same data
for Class, Gender and Survival. Table
.
emphasizes the different survival rates of
men and women in all classes, whereas the arrangement in Table
.
emphasizes
the notion that the lower the passenger class, the lower the survival rate, to for both
women andmen.hesedifferent tables arise because theorderof the variables Class
and Gender can be changed.
Figures
.
and
.
each show a three-dimensional mosaicplot of
Class
,
Gender
and
Survival
.Changing the orderof the variables emphasizes different aspects of the
data. he survivors are highlighted in both mosaicplots. In Fig.
.
, differences in
the survival rates of women and men are highlighted for all classes. he mosaicplot
in Fig.
.
shows the survival rates within the different classes (first, second, third
and crew) for men and women.
=
Table
.
.
Number of Survivors from the Titanic by class a
liation and Gender. here are large
differences between the survival rates of men and women across all classes
Class:
First
Second
hird
Crew
Gender:
Female Male
Female Male
Female Male
Female Male
Survived:
yes
141
62
93
25
90
88
20
192
no
4
118
13
154
106
422
3
670
Survival
97
34
88
14
46
17
87
22
Rate(in %)
Table
.
.
Number of Survivors from the Titanic by Gender and class. he survival rates decline as the
passenger class decreases
Gender:
Female
Male
Class:
First
Second hird
Crew
First
Second hird
Crew
Survived:
yes
141
93
90
20
62
25
88
192
no
4
13
106
3
118
154
422
670
Survival
97
88
46
87
34
14
17
22
Rate(in %)
