subsetting data frame by row index

Question

Why is my last step converting the data frame to a vector? I want to keep the first 6000 observations in the data frame key.

  set.seed(1)
  key         


        

Answer 1

It's being coerced to a vector basically because it can be and that's the default coercion when there's only 1 element. R is trying to be "helpful".

This will keep it as a dataframe:

set.seed(1)
key <- data.frame(matrix(NA, nrow = 10000, ncol = 1))
names(key) <- "ID"
key$ID <- replicate(10000, 
                      rawToChar(as.raw(sample(c(48:57,65:90,97:122), 8, replace=T))))
key <- unique(key)  
key <- as.data.frame(key[1:6000,]) # still a data frame