I have a column as A_Date which has date values with the class as "POSIXct" "POSIXt". Now i have tried to convert these date values into mmm-yy format as date values.
So, I have used as.yearmon() function. After converting i have checked the details. I came to know that for the date values of 01-01-2016 from 12:00 AM to 05:28 AM i am seeing the values as Dec-15 which is wrong.
If my_time is your time in POSIXct, do:
format(my_time, format = "%b-%y")
If the purpose is simply to round to the first of the month but retain the data type, use this function from lubridate
library(lubridate)
floor_date(my_time, "month")
Related
Have an large data frame where there's 2 columns (POSIXct) and need to calculate length of ride.
Dates are formatted as follows:
format: "2020-10-31 19:39:43"
Can use the difftime function, correct?
Thanks
Given your data is using the correct POSIXct format you can simply subtract two dates to get the difference. No need for additional functions.
date1 <- as.POSIXct(strptime("2020-10-31 19:39:43", format = "%Y-%m-%d %H:%M:%OS"))
date2 <- as.POSIXct(strptime("2020-10-31 19:20:43", format = "%Y-%m-%d %H:%M:%OS"))
date1 - date2
Output: Time difference of 19 mins
It depends what output format you want.
For example if you want month difference between two dates, you can use the "interval" function from library "lubridate"
library(lubridate)
interval(as.Date(df$date1),as.Date(df$date2) %/% months(1))
It also works with years, weeks, days, hours
Currently I am attempting to convert dates in the YYYYMMDD format to separate columns for year, month, and day. I know that using the as.Date function I can convert YYYYMMDD to YYYY-MM-DD, and work from there, however R is misinterpreting the dates and I'm not sure what to do. The function is converting the values into dates, but not correctly.
For example: R is converting '19030106' to '2019-03-01', when it should be '1903-01-06'. I'm not sure how to fix this, but this is the code I am using.
library(lubridate)
PrecipAll$Date <- as.Date(as.character(PrecipAll$YYYYMMDD), format = "%y%m%d")
YYYYMMDD is currently numeric, and I needed to include as.character in order for it to output a date at all, but if there are better solutions please help.
Additionally, if you have any tips on separating the corrected dates into separate Year, Month, and Date columns that would be greatly appreciated.
With {lubridate}, try ymd() to parse the YYYYMMDD varaible, regradless if it is in numeric or character form. Also use {lubridate}'s year, month, and day functions to get those variables as numeric signals.
library(lubridate)
PrecipAll <- data.frame(YYYYMMDD = c(19030106, 19100207, 20001130))
mutate(.data = PrecipAll,
date = lubridate::ymd(YYYYMMDD),
year = year(date),
month_n = month(date),
day_n = day(date))
YYYYMMDD date year month_n day_n
1 19030106 1903-01-06 1903 1 6
2 19100207 1910-02-07 1910 2 7
3 20001130 2000-11-30 2000 11 30
I have a table (tags) with a column for timestamp (ts), which is formatted as seconds since 1 Jan, 1970 GMT. I'm trying to create a date column that converts the timestamp from seconds to date and time EST.
The suggested code for R was:
tags$date<-strptime(tags$ts, "%Y-%m-%d")
tags$date<-as.POSIXct(tags$date)
But when I do this, tags$date comes up as NA. Any suggestions for what I might be doing wrong? Thanks.
You should us as.POSIXct function instead:
tags$date <- as.POSIXct(tags$ts, origin="1970-01-01", tz="US/New York")
strptime converts between character representations and dates not between timestamp and dates.
Here's a lubridate version. When we use as_datetime we don't need to explicitly specify an origin as it defaults to the desired origin.
lubridate::as_datetime(1507119276, tz='EST')
# [1] "2017-10-04 07:14:36 EST"
I'm having trouble changing date format in R. I have a vector "StartDate" with dates and time for instance in the format:
01Feb1991 00:00
I did:
as.POSIXct(as.character(bio$StartDate), format = "%d/%m/%Y %H:%M")
...but I got NAs as a result. Would there be a different way to change the vector into date format?
The format you provide has to match your string. In your case, that's '%d%b%Y %H:%M' (you don't have slashes between day, month and year, and your month is the abbreviated name, not the number).
as.POSIXct('01Feb1991 00:00', format='%d%b%Y %H:%M')
See ?strptime (mentioned in ?as.POSIXct) for various tokens you can use for dates.
I am running into some date issues when working with Dates in R.
Here's my situation-
I have a data set based on dates and finally got the Date field converted from character to Date in R using the following code
o1$Date <- as.Date(o1$Date , "%m/%d/%y")
(My dataset is o1 and Date is the name of my Date column)
My Date column has the following values
"1/1/2013" "1/1/2014" "1/10/2013" "1/10/2014" "1/11/2013" "1/11/2014"
However when I convert the Char to Date I get the following Dates
"2020-01-01" "2020-01-01" "2020-01-10" "2020-01-10" "2020-01-11"
Any suggestions on what the problem could be and how to work around it?
look at ?strptime to see the formatting options for times and dates. You need to use %Y rather than %y which is for a 2 digit year.