Three elections in three years

threepeat.R

require(tidyverse)
require(lubridate)
#Data from www.parlgov.org
dat <- read.csv("view_election.csv")
dat <- dat %>% 
	filter(election_type != "ep") %>% 
	mutate(election_date = as.Date(election_date)) %>% 
	filter(election_date > as.Date("1945-01-01")) %>% 
	distinct(country_name, election_date) %>% 
	group_by(country_name) %>% 
	arrange(election_date) %>% 
	mutate(thisYear = year(election_date),
		lastYear = c(NA, thisYear[-n()]),
		lastExact = c(NA, as.character(election_date[-n()])),
		yearBefore = c(NA, lastYear[-n()]),
		exactBefore = c(NA, lastExact[-n()]),
		yearBefore2 = c(NA, yearBefore[-n()])) %>% 
	filter(thisYear - yearBefore <= 3)

class(dat) <- "data.frame"