I have the following dataset with dates (YYYY-MM-DD):
> dates
[1] "20180412" "20180424" "20180506" "20180518" "20180530" "20180611" "20180623" "20180705" "20180717" "20180729"
I want to convert them in:
DD-MMM-YYYY but with the month being text. For example 20180412 should become 12Apr2018
Any suggestion on how to proceed?
M
You can try something like this :
# print today's date
today <- Sys.Date()
format(today, format="%B %d %Y") "June 20 2007"
where The following symbols can be used with the format( ) function to print dates 1
You need to first parse the text strings as Date objects, and then format these Date objects to your liking to have the different text output:
R> library(anytime) ## one easy way to parse dates and times
R> dates <- anydate(c("20180412", "20180424", "20180506", "20180518", "20180530",
+ "20180611", "20180623", "20180705", "20180717", "20180729"))
R> dates
[1] "2018-04-12" "2018-04-24" "2018-05-06" "2018-05-18" "2018-05-30"
[6] "2018-06-11" "2018-06-23" "2018-07-05" "2018-07-17" "2018-07-29"
R>
R> txtdates <- format(dates, "%d%b%Y")
R> txtdates
[1] "12Apr2018" "24Apr2018" "06May2018" "18May2018" "30May2018"
[6] "11Jun2018" "23Jun2018" "05Jul2018" "17Jul2018" "29Jul2018"
R>
You could use the as.Date() and format() functions:
dts <- c("20180412", "20180424", "20180506", "20180518", "20180530",
"20180611", "20180623")
format(as.Date(dts, format = "%Y%m%d"), "%d%b%Y")
More information here
Simply use as.POSIXct and as.format:
dates <- c("20180412", "20180424", "20180506")
format(as.POSIXct(dates, format="%Y%m%d"),format="%d%b%y")
Output:
[1] "12Apr18" "24Apr18" "06May18"
Related
I have the following column in my dataframe
> df$dates
[1] "01APR2020" "01JUN2020" "01MAR2020" "01MAY2020" "02APR2020" "02JUN2020"
[7] "02MAR2020"
I would like to format this to an object of Date class, so I want my output to look like this
> df$dates
[1] "01-04" "01-06" "01-03" "01-05" "02-04" "02-06"
[7] "02-03"
And I would like to order them from the oldest to the newest.
Edit:
For example I tried this but it doesn't work:
> format(as.Date("01APR2020", "%d%b%Y"), "%d-%m")
[1] NA
Thanks!
Just use the anydate() function from the anytime package
R> anydate(c("01APR2020", "01JUN2020", "01MAR2020"))
[1] "2020-04-01" "2020-06-01" "2020-03-01"
R>
It's idea is to not require a format for a variety of common and sensible date (or datetime) inputs. Once they are parsed, putting out day and months is easy too:
R> format(anydate(c("01APR2020", "01JUN2020", "01MAR2020")), "%d-%m")
[1] "01-04" "01-06" "01-03"
R>
We can use as.Date with format
df$dates <- format(as.Date(df$dates, "%d%b%Y"), "%d-%m")
df$dates
#[1] "01-04" "01-06" "01-03" "01-05" "02-04" "02-06" "02-03"
Or using lubridate
library(lubridate)
df$dates <- format(dmy(df$dates), "%d-%m")
NOTE: Both the solutions work on R 4.0
data
df <- data.frame(dates = c("01APR2020" ,"01JUN2020", "01MAR2020",
"01MAY2020", "02APR2020" ,"02JUN2020" , "02MAR2020"))
I am trying to get Date column from an excel data. The format of date in excel is like Wednesday-September 7-2011.
How do I handle dates in such format? I've read the documentation on Date and cannot find any method.
as.Date("Wednesday-September 7-2011", "%A-%B %d-%Y")
# [1] "2011-09-07"
https://www.stat.berkeley.edu/~s133/dates.html
If all your dates follow the same format, then I 'd suggest to remove the day and parse the rest, i.e.
x <- 'Wednesday - September 7 - 2011'
y <- paste(strsplit(x, ' - ')[[1]][-1], collapse = ' ')
#which gives [1] "September 7 2011"
as.POSIXct(y, format = '%B %d %Y')
#[1] "2011-09-07 EEST"
I'd probably strip out the weekday name and then parse the rest of the date. For example:
x <- "Wednesday-September 7-2011"
pos <- regexpr("-", x)
y<- (substr(x,pos+1,nchar(x)))
z<- parse_date(y, format = "%B %d-%Y")
I have three data tables in R. Each one has a date column. The tables are vix_data,gold_ohlc_data,btc_ohlc_data. They are formatted as follows:
head(vix_data$Date)
[1] 1/2/04 1/5/04 1/6/04 1/7/04 1/8/04 1/9/04
3435 Levels: 1/10/05 1/10/06 1/10/07 1/10/08 1/10/11 ... 9/9/16
head(gold_ohlc_data$date)
[1] 8/23/17 8/22/17 8/21/17 8/18/17 8/17/17 8/16/17
2519 Levels: 1/10/08 1/10/11 1/10/12 1/10/13 1/10/14 ... 9/9/16
head(btc_ohlc_data$Date)
[1] "2017-08-23" "2017-08-22" "2017-08-21" "2017-08-20" "2017-08-19"
[6] "2017-08-18"
How can I change the date column in the vix_data and gold_ohlc_data tables to match the btc_ohlc_data format? I have tried several methods, for example using as.Date to transform each column- but this usually messes up the values and inserts a lot of N/A's
An option is to use functions from the package lubridate. The users need to know which one is day and which one is month to select the right function to use, such as dmy or mdy
# Load package
library(lubridate)
# Create example string
date1 <- c("1/2/04", "1/5/04", "1/6/04", "1/7/04", "1/8/04", "1/9/04")
date2 <- c("8/23/17", "8/22/17", "8/21/17", "8/18/17", "8/17/17", "8/16/17")
# Convert to date class
dmy(date1)
# [1] "2004-02-01" "2004-05-01" "2004-06-01" "2004-07-01" "2004-08-01" "2004-09-01"
mdy(date1)
# [1] "2004-01-02" "2004-01-05" "2004-01-06" "2004-01-07" "2004-01-08" "2004-01-09"
mdy(date2)
# [1] "2017-08-23" "2017-08-22" "2017-08-21" "2017-08-18" "2017-08-17" "2017-08-16"
Look into the package lubridate. lubridate::dmy() and ymd() should handle this just fine.
It looks like your data are read in as factors, so first you'll have to change them to characters. Then after that you can convert it to a date and specify the input format where %m represents the numerical month, %d represents the day, and %y represents the 2-digit year.
x <- c('1/2/04', '1/5/04', '1/6/04', '1/7/04', '1/8/04', '1/9/04')
y <- as.Date(x, format = "%m/%d/%y")
y
[1] "2004-01-02" "2004-01-05" "2004-01-06" "2004-01-07" "2004-01-08"
[6] "2004-01-09"
Are you sure you're specifying as.Date correctly? For example, do you have %y, instead of %Y?
I did the following and it worked:
> vix <- c("1/2/04", "1/5/04", "1/6/04", "1/7/04", "1/8/04", "1/9/04")
> vix<- as.factor(vix)
> vix
[1] 1/2/04 1/5/04 1/6/04 1/7/04 1/8/04 1/9/04
Levels: 1/2/04 1/5/04 1/6/04 1/7/04 1/8/04 1/9/04
> as.Date(vix, "%m/%d/%y")
[1] "2004-01-02" "2004-01-05" "2004-01-06" "2004-01-07" "2004-01-08" "2004-01-09"
Apologies for the simple question, but I can't find help for this type of date.
April 5th, 2012 is saved as numeric as "20120405"
How can I convert a vector of such values into usable dates?
You just need the as.Date function:
R> x = "20120405"
R> as.Date(x, "%Y%m%d")
[1] "2012-04-05"
Look at the help file: ?as.Date, but essentially
%Y means year in the form 2012, use %y for 12.
%m is the month.
%d the day.
If your date had separators, say, 2012-04-05, then use something like: %Y-%m-%d. Alternatively, you can use:
R> strptime(x, "%Y%m%d")
[1] "2012-04-05"
In particular, you can pass vectors of dates to these functions, so:
R> y = c("20120405", "20121212")
R> as.Date(y, "%Y%m%d")
[1] "2012-04-05" "2012-12-12"
like this,
(foo <- as.Date("20120405", "%Y%m%d"))
# "2012-04-05"
and maybe you want to format to get the month printed out
format(foo, "%Y %b %d")
# "2012 Apr 05"
You could take a look at this page
With strptime you can convert it to POSIXlt class and with as.Date you can convert it to a Date class using format "%Y%m%d":
strptime( "20120405",format="%Y%m%d")
[1] "2012-04-05"
as.Date( "20120405",format="%Y%m%d")
[1] "2012-04-05"
Edit:
It is not really clear if you have character "20120405" or numeric 20120405. In the latter case you have to convert to character first with as.character(20120405)
You could also use the lubridate package:
library(lubridate)
ymd("20120405")
How would I convert the following character variables to dates?
strDates <- c("Jan.2008", "Feb.2008")
str(strDates)
chr [1:2] "Jan.2008" "Feb.2008"
dates <- as.Date(strDates, "%b %Y")
str(dates)
Date[1:2], format: NA NA
Any assistance would be greatly appreciated
To form a valid 'date', you also need a day which your data was lacking. So we add one, and we simply use an arbitrary day (here: first of the month):
R> strDates <- c("Jan.2008", "Feb.2008")
R> strptime(paste("01", strDates), "%d %b.%Y")
[1] "2008-01-01" "2008-02-01"
R>
A Date requires a day element as well, so you can add that to the input string with paste:
full.dates <- paste("01", strDates, sep = ".")
Specify the template correctly, including separator tokens:
as.Date(full.dates, "%d.%b.%Y")
[1] "2008-01-01" "2008-02-01"