How to Use Equivalent of SAS PROC FREQ in R


In SAS, you can use PROC FREQ to calculate frequencies for variables.

The easiest way to replicate this functionality in the R programming language is by using the table function.

The following example shows how to use this function in practice.

Example: How to Use Equivalent of SAS PROC FREQ in R

Suppose we have the following data frame in R that contains information about points scored by basketball players on various teams and positions:

#create data frame
df <- data.frame(team=c('A', 'A', 'A', 'A', 'B', 'B', 'B', 'B'),
                 position=c('G', 'G', 'G', 'F', 'G', 'F', 'F', 'C'),
                 points=c(23, 18, 14, 14, 13, 19, 34, 28))

#view data frame
df

  team position points
1    A        G     23
2    A        G     18
3    A        G     14
4    A        F     14
5    B        G     13
6    B        F     19
7    B        F     34
8    B        C     28

We can use the following code to calculate the frequency of each unique value in the position column:

#calculate frequency of each unique value in 'position' column
table(df$position)

C F G 
1 3 4  

The output shows the frequency of each unique value in the position column.

For example, we can see:

  • The value C occurs 1 time.
  • The value F occurs 3 times.
  • The value G occurs 4 times.

If you would like to view the frequencies as percentages, you can use the prop.table function as follows:

#calculate frequency percentage of each unique value in 'position' column
prop.table(table(df$position))

    C     F     G 
0.125 0.375 0.500   

The output shows the frequency percentage of each unique value in the position column.

For example, we can see:

  • The value C represents 12.5% of all values in the position column.
  • The value F represents 37.5% of all values in the position column.
  • The value G represents 50% of all values in the position column.

Lastly, if you’d like to create a two-way frequency table in R then you can include the names of two columns in the table function as follows:

#calculate frequencies of values in team and position columns
table(df$team, df$position)

    C F G
  A 0 1 3
  B 1 2 1   

The output shows the frequency of each unique combination of values in the team and position columns.

For example, we can see:

  • There were 0 occurrences of position C on team A.
  • There was 1 occurrence of position F on team A.
  • There were 3 occurrences of position G on team A.

And so on.

Additional Resources

The following tutorials explain how to perform other common operations in R:

How to Import SAS Files into R
How to Create a Frequency Polygon in R
How to Create Tables in R

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