Section 36 Three-way Relationships
Relationship between three or more variables - a combination of a set of continuous and categorical variables.
36.1 Tabulation
We can still produce summary statistics to capture relationship between continuous and a set of categorical variables.
weather <- read.csv('weather.csv')
with(data=weather,
tapply(X = humidity,
INDEX = list(rain, winddir),
FUN = median)) Calm East North South West
Dry 95 88.0 73.5 74 82
Wet 91 95.5 89.0 90 89 Calm East North South West
Dry -0.08461538 3.057143 5.338889 7.3 3.729870
Wet 2.70000000 3.583333 5.240000 3.6 3.841176, , rain = Dry
winddir
windsp Calm East North South West
0 13 0 0 0 0
2 0 0 0 2 0
3 0 0 0 0 0
4 0 0 1 1 0
5 0 2 1 1 3
6 0 2 2 3 0
7 0 0 0 4 4
8 0 1 2 2 2
9 0 1 1 2 10
10 0 2 0 0 8
11 0 1 1 0 9
12 0 1 1 0 11
13 0 1 1 0 4
14 0 1 3 0 4
15 0 0 2 0 5
16 0 1 1 0 3
17 0 0 1 0 0
18 0 0 1 0 2
19 0 1 0 0 2
20 0 0 0 0 5
21 0 0 0 0 1
22 0 0 0 0 2
23 0 0 0 0 1
24 0 0 0 0 0
25 0 0 0 0 1
, , rain = Wet
winddir
windsp Calm East North South West
0 1 0 0 0 0
2 0 0 0 0 0
3 0 0 0 0 1
4 0 0 0 0 0
5 0 0 0 1 0
6 0 0 0 0 1
7 0 0 0 1 0
8 0 0 0 0 1
9 0 0 0 0 2
10 0 0 0 0 0
11 0 1 0 0 0
12 0 0 0 0 2
13 0 0 0 0 2
14 0 0 1 0 0
15 0 2 0 0 0
16 0 0 3 0 2
17 0 0 0 0 0
18 0 0 0 0 0
19 0 0 1 0 2
20 0 1 0 0 0
21 0 0 0 0 0
22 0 0 0 0 2
23 0 0 0 0 2
24 0 2 0 0 0
25 0 0 0 0 0