Module 9 Assignment

This weeks assignment is based around two questions, the first is to generate a simple table in R that consists of four rows: Country, age, salary, and purchased. The following code is used to generate that.

# 1. Simple table
assignment_data <- data.frame( Country = c("France","Spain","Germany","Spain","Germany", "France","Spain","France","Germany","France"), 
                               age = c(44,27,30,38,40,35,52,48,45,37), 
                               salary = c(6000,5000,7000,4000,8000), 
                               Purchased=c("No","Yes","No","No","Yes", "Yes","No","Yes","No","Yes"))
print(assignment_data)

The second is used to generate a contingency table known as a rx C table using the mtcars dataset. In addition to this, there must be a report on the sum of the rows and columns, the proportional weight of each value in the table, and the row proportions of the table. This can be seen in the following code.

# 2. Contingency table
library(datasets)
data(mtcars)
assignment9 <- table(mtcars$gear, mtcars$cyl, dnn=c("gears", "cylinders"))
print(assignment9)

# 2.1 Add margins
assignment9_margins <- addmargins(assignment9)
print(assignment9_margins)

# 2.2 Proportional table
assignment9_prop <- prop.table(assignment9)
print(assignment9_prop)

# 2.3 Row proportions
assignment9_row_prop <- prop.table(assignment9, margin = 1)
print(assignment9_row_prop)

The complete code with outputs would be:

> # 1. Simple table
> assignment_data <- data.frame( Country = c("France","Spain","Germany","Spain","Germany", "France","Spain","France","Germany","France"), 
+                                age = c(44,27,30,38,40,35,52,48,45,37), 
+                                salary = c(6000,5000,7000,4000,8000), 
+                                Purchased=c("No","Yes","No","No","Yes", "Yes","No","Yes","No","Yes"))
> print(assignment_data)
   Country age salary Purchased
1   France  44   6000        No
2    Spain  27   5000       Yes
3  Germany  30   7000        No
4    Spain  38   4000        No
5  Germany  40   8000       Yes
6   France  35   6000       Yes
7    Spain  52   5000        No
8   France  48   7000       Yes
9  Germany  45   4000        No
10  France  37   8000       Yes
> 
> # 2. Contingency table
> library(datasets)
> data(mtcars)
> assignment9 <- table(mtcars$gear, mtcars$cyl, dnn=c("gears", "cylinders"))
> print(assignment9)
     cylinders
gears  4  6  8
    3  1  2 12
    4  8  4  0
    5  2  1  2
> 
> # 2.1 Add margins
> assignment9_margins <- addmargins(assignment9)
> print(assignment9_margins)
     cylinders
gears  4  6  8 Sum
  3    1  2 12  15
  4    8  4  0  12
  5    2  1  2   5
  Sum 11  7 14  32
> 
> # 2.2 Proportional table
> assignment9_prop <- prop.table(assignment9)
> print(assignment9_prop)
     cylinders
gears       4       6       8
    3 0.03125 0.06250 0.37500
    4 0.25000 0.12500 0.00000
    5 0.06250 0.03125 0.06250
> 
> # 2.3 Row proportions
> assignment9_row_prop <- prop.table(assignment9, margin = 1)
> print(assignment9_row_prop)
     cylinders
gears          4          6          8
    3 0.06666667 0.13333333 0.80000000
    4 0.66666667 0.33333333 0.00000000
    5 0.40000000 0.20000000 0.40000000
>