R - delete consecutive (ONLY) duplicates

Question

I need to eliminate rows from a data frame based on the repetition of values in a given column, but only those that are consecutive. For example, for the following data fram

Answer 1

Here is a data.table solution. The trick is to create a shifted version of x with the shift function and compare it with x

library(data.table)
dattab <- as.data.table(df)
dattab[x != shift(x = x, n = 1, fill = -999, type = "lead")] # edited to add closing )

This way you compare each value of x with its immediately following value and throw out where they match. Make sure to set fill to something that is not in x in order for correct handling of the last value.