generate histogram in R for employee -

below dataset containing records of employee attendance

         date   intime  outtime 2  02/11/2015 10:21:27 17:58:12 3  03/11/2015 10:13:09 18:52:44 4  04/11/2015 10:11:52 18:40:36 5  05/11/2015 10:31:42 18:16:57 6  06/11/2015 10:13:13 18:36:15 10 10/11/2015 10:03:20 18:07:52 11 11/11/2015 09:40:20 18:42:20 12 12/11/2015 10:38:56 18:37:20 13 13/11/2015 10:45:26 18:09:54 16 16/11/2015 10:13:13 18:36:15 17 17/11/2015 10:11:43 18:36:15 18 18/11/2015 10:13:13 18:36:15 19 19/11/2015 10:13:13 18:36:15 20 20/11/2015 12:14:25 20:25:08 23 23/11/2015 10:08:08 17:57:35 24 24/11/2015 14:30:32 18:36:15 

the total time served employee in hours :

total_time <- with(newdata, sum(pmin(newdata$outtime, "18:00:00") -                                  pmax(newdata$intime, "08:00:00")   )) total_time <- 24*floor(as.numeric(total_time)) "total time served employee : 96 hours" 

i want generate histogram each employee showing hours served on monthly basis having total of 5 bins.

i changed data such had info more months: ( better histogram)

library(data.table) df = fread("    date   intime  outtime            02/11/2015 10:21:27 17:58:12            03/11/2015 10:13:09 18:52:44            04/11/2015 10:11:52 18:40:36            05/11/2015 10:31:42 18:16:57            06/11/2015 10:13:13 18:36:15            10/11/2015 10:03:20 18:07:52            11/11/2015 09:40:20 18:42:20            12/11/2015 10:38:56 18:37:20            13/11/2015 10:45:26 18:09:54            16/11/2015 10:13:13 18:36:15            17/11/2015 10:11:43 18:36:15            18/11/2015 10:13:13 18:36:15            19/11/2015 10:13:13 18:36:15            20/11/2015 12:14:25 20:25:08            23/11/2015 10:08:08 17:57:35            24/11/2015 14:30:32 18:36:15")   df$intime <- as.posixct(df$intime, format = "%h:%m:%s")  df$outtime <- as.posixct(df$outtime, format = "%h:%m:%s")  library(lubridate) #to extract day df$day <- dmy(df$date) df$day <- day(df$day)  df$total_time <- difftime(pmin(df$outtime, as.posixct("18:00:00", format = "%h:%m:%s")),                         pmax(df$intime, as.posixct("08:00:00", format = "%h:%m:%s")), units = "hours") df$total_time <- as.numeric(df$total_time)  library(ggplot2) ggplot(df, aes(x = day, y= total_time))+geom_histogram(stat = "identity", bins = 5) 

---

with 5 bins (only 4 bins appear in plot because no data 24-30 day's intervals) :

df$breaks <- cut(df$day, breaks = c(0,5,10,15,30,max(df$day))) df1=ddply(df, "breaks", summarise, "total_hr"=sum(total_time)) ggplot(df1, aes(x = breaks, y= total_hr))+   geom_histogram(stat = "identity", bins = 5, binwidth = 0)