Counting how many times a variable has a certain value.

[ghel]

I have a dataset with around 700 observations with a variable, X, which has values between 1 and 19. I would like to make a table counting how many times X has the value 1, the value 2 etc.

Anyone here that has any good ideas?

Thanks!

[startz]

I'm sure there is a more elegant way to do this, but...

X <- floor(20*runif(700)) # generate fake data, although it will include 0's
values <- unique(X) # find possible values
counts <- rep(0,length(values)) # space to save counts
for (i in seq_along(values)){
  counts[i] <- sum(X == values[i]) # take advantage that TRUE adds as 1.0
}

[FJCC]

I think you want the table() function.

X <- sample(1:19,size = 20,replace = TRUE)
X
 [1] 15  5  8 19 10 18 10 12  2 10 12 14 17 14  3  8 14 19 15 17
table(X)
X
 2  3  5  8 10 12 14 15 17 18 19 
 1  1  1  2  3  2  3  2  2  1  2 

[startz]

@FJCC's suggestion is certainly more R-elegant than mine.

[martin.R]

Assuming your data is in a dataframe df (otherwise you can convert it):

dplyr::count(df, X)