I have dataset where time.start vary from 5:00:00 to 28:59:59 (i.e. 01.01.2013 28:00:00 is actually 02.01.2013 04:00:00). Dates are in %d.%m.%Y format.
Date Time.start
01.01.2013 22:13:07
01.01.2013 22:52:23
01.01.2013 23:34:06
01.01.2013 23:44:25
01.01.2013 27:18:48
01.01.2013 28:41:04
I want to convert it to normal date format.
dates$date <- paste(dates$Date,dates$Time.start, sep = " ")
dates$date <- as.POSIXct(strptime(dates$date, "%m.%d.%Y %H:%M:%S"))
But obviously I have NA for time > 23:59:59
How should I modify my code?
E.g. add the time as seconds to the date:
df <- read.table(header=T, text=" Date Time.start
01.01.2013 22:13:07
01.01.2013 22:52:23
01.01.2013 23:34:06
01.01.2013 23:44:25
01.01.2013 27:18:48
01.01.2013 28:41:04", stringsAsFactors=FALSE)
as.POSIXct(df$Date, format="%d.%m.%Y") +
sapply(strsplit(df$Time.start, ":"), function(t) {
t <- as.integer(t)
t[3] + t[2] * 60 + t[1] * 60 * 60
})
# [1] "2013-01-01 22:13:07 CET" "2013-01-01 22:52:23 CET" "2013-01-01 23:34:06 CET"
# [4] "2013-01-01 23:44:25 CET" "2013-01-02 03:18:48 CET" "2013-01-02 04:41:04 CET"
Just a modification of lukeAs solution:
with(df, as.POSIXct(Date, format="%d.%m.%Y")+
colSums(t(read.table(text=Time.start, sep=":",header=F))*c(3600,60,1)))
[1] "2013-01-01 22:13:07 EST" "2013-01-01 22:52:23 EST"
[3] "2013-01-01 23:34:06 EST" "2013-01-01 23:44:25 EST"
[5] "2013-01-02 03:18:48 EST" "2013-01-02 04:41:04 EST"
Using lubridate:
with(dates, mdy(Date) + hms(Time.start))
Generates:
[1] "2013-01-01 22:13:07 UTC" "2013-01-01 22:52:23 UTC"
[3] "2013-01-01 23:34:06 UTC" "2013-01-01 23:44:25 UTC"
[5] "2013-01-02 03:18:48 UTC" "2013-01-02 04:41:04 UTC"
Related
I am trying to use lubridate to process the results of a differential equation solved using ode. My simulation begins on a certain date (01-01-2021) and is on the order of days (a one unit-time increase is equal to a one day calendar time increase). How can I use lubridate to process a continuous double of time since simulation start?
For ex, I want to go from the left column to the right column:
ODE time
Calendar Time
0.0
01-01-2021 00:00
0.5
01-01-2021 12:00
1.0
01-02-2021 00:00
etc...
Thank you
I am not fully sure I understand your question. But from your example it appears you want to create timesteps. When I understand it correctly, a "one unit" is a adding 24 hours, while the half day is adding 12 hours. Your data frame example suggest you want to have this in a dataframe/tibble.
With {lubridate} you can "coerce" datetimestamps. There are some handy time formatting functions. From a character you can go to a timestamp.
For example
# create dataframe/tibble of ODE and Calendar times
mydata <- tribble(
~ODE_time, ~Calendar_Time
,0.0 , "01-01-2021 00:00"
,0.5 , "01-01-2021 12:00"
,1.0 , "01-02-2021 00:00"
,1.5 , "01-02-2021 12:00"
)
mydata <- mydata %>%
mutate(time = lubridate::mdy_hm(Calendar_Time))
In your case, I use the mdy_hm() function to make a timestamp (dttm) object.
I assign it to the time variable/column so you can check the presentation in R/RStudio.
What I get from your question is that you want to create a sequence of timestamps.
Here you can use the seq() function and work with the time offset, in your case 12 hours (or half a day). I limit the length out to 10 ... you can obviously define longer sequences or determine your end day (i.e. to parameter of seq())
date_time_seq <- seq( from = lubridate::mdy_hm("01-01-2021 00:00")
,length.out = 10,
,by = "12 hours")
This gives you a sequence of timestamps
date_time_seq
[1] "2021-01-01 00:00:00 UTC" "2021-01-01 12:00:00 UTC" "2021-01-02 00:00:00 UTC"
[4] "2021-01-02 12:00:00 UTC" "2021-01-03 00:00:00 UTC" "2021-01-03 12:00:00 UTC"
[7] "2021-01-04 00:00:00 UTC" "2021-01-04 12:00:00 UTC" "2021-01-05 00:00:00 UTC"
[10] "2021-01-05 12:00:00 UTC"
The syntax allows you to add various "steps" and you can use increments of different time units, e.g. mins, hours, days, weeks, etc.
This timestep vector you can operate in your dataframe/tibble and perform your other operations.
Good luck!
You could directly add the number of seconds to the start date:
ODETime <- seq(0,10,by=0.5)
calendarTime <- as.POSIXct("2021-01-01 00:00") + ODETime * 86400
calendarTime
[1] "2021-01-01 00:00:00 CET" "2021-01-01 12:00:00 CET" "2021-01-02 00:00:00 CET"
[4] "2021-01-02 12:00:00 CET" "2021-01-03 00:00:00 CET" "2021-01-03 12:00:00 CET"
[7] "2021-01-04 00:00:00 CET" "2021-01-04 12:00:00 CET" "2021-01-05 00:00:00 CET"
[10] "2021-01-05 12:00:00 CET" "2021-01-06 00:00:00 CET" "2021-01-06 12:00:00 CET"
[13] "2021-01-07 00:00:00 CET" "2021-01-07 12:00:00 CET" "2021-01-08 00:00:00 CET"
[16] "2021-01-08 12:00:00 CET" "2021-01-09 00:00:00 CET" "2021-01-09 12:00:00 CET"
[19] "2021-01-10 00:00:00 CET" "2021-01-10 12:00:00 CET" "2021-01-11 00:00:00 CET"
or with lubridate:
as.POSIXct("2021-01-01 00:00") + lubridate::period(24,'hour') * ODETime
[1] "2021-01-01 00:00:00 CET" "2021-01-01 12:00:00 CET" "2021-01-02 00:00:00 CET"
[4] "2021-01-02 12:00:00 CET" "2021-01-03 00:00:00 CET" "2021-01-03 12:00:00 CET"
[7] "2021-01-04 00:00:00 CET" "2021-01-04 12:00:00 CET" "2021-01-05 00:00:00 CET"
[10] "2021-01-05 12:00:00 CET" "2021-01-06 00:00:00 CET" "2021-01-06 12:00:00 CET"
[13] "2021-01-07 00:00:00 CET" "2021-01-07 12:00:00 CET" "2021-01-08 00:00:00 CET"
[16] "2021-01-08 12:00:00 CET" "2021-01-09 00:00:00 CET" "2021-01-09 12:00:00 CET"
[19] "2021-01-10 00:00:00 CET" "2021-01-10 12:00:00 CET" "2021-01-11 00:00:00 CET"
I am working in R.
I have to generate a series of dates and times. In particular, I would like to have two data points per day, hence to assign twice each date with a different time, for instance:
"2001-05-13 00:00:00"
"2001-05-13 12:00:00"
"2001-05-14 00:00:00"
"2001-05-14 12:00:00"
I found the following code to produce a series of dates:
seq(as.Date("2000/1/1"), as.Date("2003/1/1"), by = 0.5)
Nevertheless, even if I set the by = 0.5, the code returns only a date , not a datetime.
Any idea how to produce a series of datetimes?
as.Date will produce only dates, use as.POSIXct to produce date-time.
seq(as.POSIXct("2000-01-01 00:00:00", tz = 'UTC'),
as.POSIXct("2003-01-01 00:00:00", tz = 'UTC'), by = '12 hours')
# [1] "2000-01-01 00:00:00 UTC" "2000-01-01 12:00:00 UTC"
# [3] "2000-01-02 00:00:00 UTC" "2000-01-02 12:00:00 UTC"
# [5] "2000-01-03 00:00:00 UTC" "2000-01-03 12:00:00 UTC"
# [7] "2000-01-04 00:00:00 UTC" "2000-01-04 12:00:00 UTC"
# [9] "2000-01-05 00:00:00 UTC" "2000-01-05 12:00:00 UTC"
#[11] "2000-01-06 00:00:00 UTC" "2000-01-06 12:00:00 UTC"
#[13] "2000-01-07 00:00:00 UTC" "2000-01-07 12:00:00 UTC"
#...
#...
Can anyone tell me why I do have only 1895 elements instead of 1896(79 days X 24 hours)?
time_index <- seq(from = as.POSIXct("2017-01-02 01:00"),
to = as.POSIXct("2017-03-21 24:00"), by = "hour")
length(time_index)
# >[1] 1895
daylight saving ?
time_index[1655:1660]
[1] "2017-03-11 23:00:00 EST" "2017-03-12 00:00:00 EST"
[3] "2017-03-12 01:00:00 EST" "2017-03-12 03:00:00 EDT"
[5] "2017-03-12 04:00:00 EDT" "2017-03-12 05:00:00 EDT"
to stop it from happening one must choose a time zone where there is no daylight saving, here is an example
time_index <- seq(from = as.POSIXct("2017-01-02 01:00",tz = 'UTC'),
to = as.POSIXct("2017-03-21 24:00", tz = 'UTC'),
by = "hour")
length(time_index)
[1] 1896
I am trying to create a time series with 30 min intervals. I used the following command with the output also shown:
ts = seq(as.POSIXct("2009-01-01 00:00"), as.POSIXct("2014-12-31 23:30"),by = "hour")
"2010-02-21 12:00:00 EST" "2010-02-21 13:00:00 EST" "2010-02-21 14:00:00 EST"
When I change it to by ="min" it changes to be every minute.
How do I create a time series with every 30 minute intervals?
You can specify minutes in the by argument, and pass the time zone "UTC" as Adrian pointed out. Check ?seq.POSIXt for more details about the by argument specified as a character string:
A character string, containing one of "sec", "min", "hour", "day",
"DSTday", "week", "month", "quarter" or "year". This can optionally be
preceded by a (positive or negative) integer and a space, or followed
by "s".
ts <- seq(as.POSIXct("2017-01-01", tz = "UTC"),
as.POSIXct("2017-01-02", tz = "UTC"),
by = "30 min")
head(ts)
Output
[1] "2017-01-01 00:00:00 UTC"
[2] "2017-01-01 00:30:00 UTC"
[3] "2017-01-01 01:00:00 UTC"
[4] "2017-01-01 01:30:00 UTC"
[5] "2017-01-01 02:00:00 UTC"
[6] "2017-01-01 02:30:00 UTC"
Default units are seconds. So just do 1800 seconds to get 30 minutes.
ts = seq(as.POSIXct("2009-01-01 00:00"), as.POSIXct("2014-12-31 23:30"),by = 1800)
ts[1:20]
[1] "2009-01-01 00:00:00 EST" "2009-01-01 00:30:00 EST" "2009-01-01 01:00:00 EST" "2009-01-01 01:30:00 EST" "2009-01-01 02:00:00 EST"
[6] "2009-01-01 02:30:00 EST" "2009-01-01 03:00:00 EST" "2009-01-01 03:30:00 EST" "2009-01-01 04:00:00 EST" "2009-01-01 04:30:00 EST"
[11] "2009-01-01 05:00:00 EST" "2009-01-01 05:30:00 EST" "2009-01-01 06:00:00 EST" "2009-01-01 06:30:00 EST" "2009-01-01 07:00:00 EST"
[16] "2009-01-01 07:30:00 EST" "2009-01-01 08:00:00 EST" "2009-01-01 08:30:00 EST" "2009-01-01 09:00:00 EST" "2009-01-01 09:30:00 EST"
I want to generate a working week / working day sequence (Monday-Friday; 8am - 5pm) in R. However I only figured out how to extract a working week (Monday-Friday) with 24 hours.
library(timeDate)
start <- as.POSIXct("2010-01-01")
interval <- 60
seq_1 <- as.timeDate(seq(from=start, by=interval*60, length.out = 200))
seq_2 <- seq_1[isWeekday(seq_1)]; seq_2
dayOfWeek(seq_2)
Is there a similar function which can extract only working hours? Thanks
You can use function format to obtain hours
seq_2[as.numeric(format(seq_2,'%H')) %in% 8:15 ]
Select weekdays and then repeat with frequency equal to the desired hours. I'm afraid I missed your 8 o;clock start and used the phrase "9 to 5" as my guide:
twoyears <- seq.Date(as.Date("2010-01-01"), by='day', length.out=365*2)
twoworkyrs <- twoyears[isWeekday(twoyears, wday = 1:5)]
twoworkyrs[ 1:10]
# [1] "2010-01-01" "2010-01-04" "2010-01-05" "2010-01-06" "2010-01-07" "2010-01-08"
# [7] "2010-01-11" "2010-01-12" "2010-01-13" "2010-01-14"
workhours <- as.POSIXct( as.numeric(rep(twoworkyrs, each=9))*24*3600 + # weekdays
(9:17)*3600 , n # working hours
origin="1970-01-01", tz="America/LosAngeles")
#----- First two weeks ----------------
> workhours[1:90]
[1] "2010-01-01 09:00:00 UTC" "2010-01-01 10:00:00 UTC" "2010-01-01 11:00:00 UTC"
[4] "2010-01-01 12:00:00 UTC" "2010-01-01 13:00:00 UTC" "2010-01-01 14:00:00 UTC"
[7] "2010-01-01 15:00:00 UTC" "2010-01-01 16:00:00 UTC" "2010-01-01 17:00:00 UTC"
[10] "2010-01-04 09:00:00 UTC" "2010-01-04 10:00:00 UTC" "2010-01-04 11:00:00 UTC"
[13] "2010-01-04 12:00:00 UTC" "2010-01-04 13:00:00 UTC" "2010-01-04 14:00:00 UTC"
[16] "2010-01-04 15:00:00 UTC" "2010-01-04 16:00:00 UTC" "2010-01-04 17:00:00 UTC"
[19] "2010-01-05 09:00:00 UTC" "2010-01-05 10:00:00 UTC" "2010-01-05 11:00:00 UTC"
[22] "2010-01-05 12:00:00 UTC" "2010-01-05 13:00:00 UTC" "2010-01-05 14:00:00 UTC"
[25] "2010-01-05 15:00:00 UTC" "2010-01-05 16:00:00 UTC" "2010-01-05 17:00:00 UTC"
[snipped
I must admit that timezone conversions are one of my weakest suits.