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rdplyrfrequencyanalysis

frequency count of multiple variables in R

I have multiple variables in my dataframe. I want to check the individual frequency counts of some of the selected variables more from QA perspective of large datasets.e.g 

ID Q1 Q2 Q3
1  1  2  3
2  2  1  2 
3  3  2  1
4  1  2  3
5  2  3  1

So, I should get the frequency count of Q1 & Q2, my selected variables, as the output below 

Q1 1 - 2
   2 - 2
   3 - 1

Q2 1 - 1
   2 - 3
   3 - 1

I tried table(), but it seeems like I would have to write this function multiple times which I want to avoid. 

table(df$Q1)
table(df$Q2)

Is there any other way to achieve this?

Solution

  • You can use apply with table

    apply(df[-1], 2, table)

#  Q1 Q2 Q3
#1  2  1  2
#2  2  3  1
#3  1  1  2

    Or if you want it for selected rows only which you want to specify using their names you can use, 

    apply(df[c("Q1", "Q2")], 2, table)


#  Q1 Q2
#1  2  1
#2  2  3
#3  1  1