Question

R PROGRAMMING QUESTION

To try and get the frequency of variable within a column, I used the following code:

    s = table(student$Sport)
    t = as.data.frame(s)
    names(t)[1] = 'Sport'
    t

Although this works, it gives me a massive list that is not sorted, such as this:

    1            Football    20310
    2            Rugby    80302
    3            Tennis    5123
    4            Swimming    73132
    …            …                    …
    68           Basketball           90391

How would I go about sorting this table, so that the most frequent sport is at the top.

Also, is there a way to only display the top 5 options? Rather than all 68 different sports?

Any help would be appreciated!

Answer 1

Yes of course!

I'll take an example of "cars" data from R and explain.

So cars looks like this:

cars
speed dist
1 4 2
2 4 10
3 7 4
4 7 22
5 8 16
6 9 10
7 10 18
8 10 26
9 10 34
10 11 17
11 11 28
12 12 14
13 12 20

Now suppose you want to order it by column 1: The command is very simple

new = cars[order(cars[,1]),] ## Increasing

new = cars[order(-cars[,1]),] ## decreasing

How does it works?

Here we chose a column and order it. It gives us a permutation in increasing order. Then cars[order,] structure rearranges rows at that permutation giving you an ordered data frame.

Now if you want to display 5 rows only:

type:

cars[1:5,]

if you want to display 1,3,6,14th rows,

x<- c(1,3,6,14)

cars[x,]