retention: Retention
In lovetoken/useful.lovetoken: Useful functions for lovetoken

Retention

1	retention(x, by = c("days", "weeks", "months"), plot = T)

`x`	input data frame. Must be input first column an ID value and the second column a datetype value.
`by`	Set the interval.
`plot`	Turn on plot option about retention. Default is TRUE

set.seed(1004)
library(lubridate)
connect_log <- data.frame(
  id = c(1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5, 5),
  login_date = sample(seq(ymd_h(2018010100), ymd_h(2018010323), by = "hour"), 20)
) %>%
  arrange(id, login_date)

retention(connect_log, by = "days")