Take the subsets of a data.frame with the same feature and select a single row from each subset

Question

Suppose I have a matrix in R as follows:

ID Value
1 10
2 5
2 8
3 15
4 7
4 9
...

What I need is a random sample where every element is repre

Answer 1

You can do that with dplyr like so:

library(dplyr)
df %>% group_by(ID) %>% sample_n(1)