I imported a CSV file with dates from a SQL query, but the dates are really date-time values and R doesn't seem to recognize them as dates:
> mydate
[1] 1/15/2006 0:00:00
2373 Levels: 1/1/2006 0:00:00 1/1/2007 0:00:00 1/1/2008 0:00:00 ... 9/9/2012 0:00:00
> class(mydate)
[1] "factor"
> as.Date(mydate)
Error in charToDate(x) :
character string is not in a standard unambiguous format
How do I convert mydate to date format? (I don't need to include the time portion.)
You were close. format= needs to be added to the as.Date call:
mydate <- factor("1/15/2006 0:00:00")
as.Date(mydate, format = "%m/%d/%Y")
## [1] "2006-01-15"
You can try lubridate package which makes life much easier
library(lubridate)
mdy_hms(mydate)
The above will change the date format to POSIXct
A sample working example:
> data <- "1/15/2006 01:15:00"
> library(lubridate)
> mydate <- mdy_hms(data)
> mydate
[1] "2006-01-15 01:15:00 UTC"
> class(mydate)
[1] "POSIXct" "POSIXt"
For case with factor use as.character
data <- factor("1/15/2006 01:15:00")
library(lubridate)
mydate <- mdy_hms(as.character(data))
Take a look at the formats in ?strptime
R> foo <- factor("1/15/2006 0:00:00")
R> foo <- as.Date(foo, format = "%m/%d/%Y %H:%M:%S")
R> foo
[1] "2006-01-15"
R> class(foo)
[1] "Date"
Note that this will work even if foo starts out as a character. It will also work if using other date formats (as.POSIXlt, as.POSIXct).
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 imported a CSV file with dates from a SQL query, but the dates are really date-time values and R doesn't seem to recognize them as dates:
> mydate
[1] 1/15/2006 0:00:00
2373 Levels: 1/1/2006 0:00:00 1/1/2007 0:00:00 1/1/2008 0:00:00 ... 9/9/2012 0:00:00
> class(mydate)
[1] "factor"
> as.Date(mydate)
Error in charToDate(x) :
character string is not in a standard unambiguous format
How do I convert mydate to date format? (I don't need to include the time portion.)
You were close. format= needs to be added to the as.Date call:
mydate <- factor("1/15/2006 0:00:00")
as.Date(mydate, format = "%m/%d/%Y")
## [1] "2006-01-15"
You can try lubridate package which makes life much easier
library(lubridate)
mdy_hms(mydate)
The above will change the date format to POSIXct
A sample working example:
> data <- "1/15/2006 01:15:00"
> library(lubridate)
> mydate <- mdy_hms(data)
> mydate
[1] "2006-01-15 01:15:00 UTC"
> class(mydate)
[1] "POSIXct" "POSIXt"
For case with factor use as.character
data <- factor("1/15/2006 01:15:00")
library(lubridate)
mydate <- mdy_hms(as.character(data))
Take a look at the formats in ?strptime
R> foo <- factor("1/15/2006 0:00:00")
R> foo <- as.Date(foo, format = "%m/%d/%Y %H:%M:%S")
R> foo
[1] "2006-01-15"
R> class(foo)
[1] "Date"
Note that this will work even if foo starts out as a character. It will also work if using other date formats (as.POSIXlt, as.POSIXct).
I coded the below in R and I want to see the hour,time and second format.
However, when I ran the code, it just shows the year,month and day even though I specified the format correctly.
> val <- 12016539307200
> valD <- as.Date(as.POSIXct(val, origin="1970-01-01"),format="%Y%m%d %H%M%S")
> valD
[1] "382758-12-22"
Could you give me a way to solve this issue?
Because it is a Date object, representing a calendar date. To have an object representing time, keep it in POSIXct:
> val <- 12016539307200
> valD <- as.POSIXct(val, origin="1970-01-01", tz = "UTC")
> valD
[1] "382758-12-22 01:20:00 UTC"
If it contains milliseconds, you go for the following:
as.POSIXct(val/1000, origin="1970-01-01")
"2350-10-16 09:35:07 CEST"
or
library(anytime)
anytime(12016539307200/1000)
"2350-10-16 09:35:07 CEST"
My data contains some date fields in this format yyyy-mm-dd
id <- c(1,2,3,4,5)
d1 <- c("2001-01-01", "1999-12-01","2007-11-31", "1995-05-01", "2013-01-07")
datadd <- data.frame(id,d1)
I need to convert date field d1 to the following format mm/dd/yyyy h:mm:ss
So the data looks like:
id d1
1 1/1/2001 0:00:00
2 12/1/1999 0:00:00
3 11/13/2007 0:00:00
4 5/1/1995 0:00:00
5 1/7/2013 0:00:00
Just use strptime (or as.Date) and format:
> format(strptime(datadd$d1, format = "%Y-%m-%d"), "%m/%d/%Y %H:%M:%S")
[1] "01/01/2001 00:00:00" "12/01/1999 00:00:00" "11/13/2007 00:00:00"
[4] "05/01/1995 00:00:00" "01/07/2013 00:00:00"
## format(as.Date(datadd$d1), "%m/%d/%Y %H:%M:%S")
I suppose you can use some gsub too if you want to remove the leading zeroes for single digit days and months.
the lubridatepackage is your friend. It's really intuitive.
## install and launch the {lubridate} package
> dt <- "1/1/2001 0:10:00"
> dt2 <- mdy_hms(dt)
[1] "2001-01-01 00:10:00 UTC"
I have a file that formats time stamps like 25/03/2011 9:15:00 p.m.
How can I parse this text to a Date-Time class with either strptime or as.POSIXct?
Here is what almost works:
> as.POSIXct("25/03/2011 9:15:00", format="%d/%m/%Y %I:%M:%S", tz="UTC")
[1] "2011-03-25 09:15:00 UTC"
Here is what is not working, but I'd like to have working:
> as.POSIXct("25/03/2011 9:15:00 p.m.", format="%d/%m/%Y %I:%M:%S %p", tz="UTC")
[1] NA
I'm using R version 2.13.2 (2011-09-30) on MS Windows. My working locale is "C":
Sys.setlocale("LC_TIME", "C")
It appears the AM/PM indicator can't include punctuation. Try it after removing the punctuation:
td <- "25/03/2011 9:15:00 p.m."
tdClean <- gsub("(.)\\.?[Mm]\\.?","\\1m",td)
as.POSIXct(tdClean, format="%d/%m/%Y %I:%M:%S %p", tz="UTC")
# [1] "2011-03-25 21:15:00 UTC"
Just came across this, as another option you can use stringr package.
library(stringr)
data$date2 <- str_sub(data$date, end = -4)
# this removes the punctuation but holds onto the A/P values
data$date2 <- str_c(data$date2, 'm')
# adds the required m