Count number of occurences in date range in R

Question

I have a dataframe with a number of accounts, their status and the start and endtime for that status. I would like to report on the number of accounts in each of these statuses

Answer 1

We can use sapply to do this for us:

report$NumberOpen <- 
    sapply(report$date, function(x)
    sum(as.Date(df1$startdate) < as.Date(x) &
    as.Date(df1$enddate) > as.Date(x) & 
    df1$state == 'Open'))

#  report
#         date NumberOpen
# 1 2016-04-01          2
# 2 2016-04-02          2
# 3 2016-04-03          2
# 4 2016-04-04          1
# 5 2016-04-05          1
# 6 2016-04-06          1

data

df1 <- data.frame(account = c(1,1,2,3),
                 state = c("Open","Closed","Open","Open"),
                 startdate = c("2016-01-01","2016-04-04","2016-03-02","2016-08-01"), 
                 enddate = c("2016-04-04","2999-01-01","2016-05-02","2016-08-05")
)

report <- data.frame(date = seq(from = as.Date("2016-04-01"),by="1 day", length.out = 6)
)