CODEWITHSUNDEEP
rdatetimedplyr
Lynn
Lynn

Reputation: 4408

Filter to a specific date within a specific column

I have a dataframe, df with column DateTimeUTC.

                         ID              DateTimeUTC

                         A               12/4/2019 11:30:30 PM
                         A               12/4/2019 11:30:30 PM
                         B               12/5/2019 11:30:30 PM
                         B               12/5/2019 11:30:30 PM
                         B               12/5/2019 11:30:30 PM

I would like to filter, so that DateTimeUTC only displays dates from 12/5/2019, with this outcome:

                           ID              DateTimeUTC


                         B               12/5/2019 11:30:30 PM
                         B               12/5/2019 11:30:30 PM
                         B               12/5/2019 11:30:30 PM

I have tried this command, but have not been successful:

                       library('dplyr')
                       library('lubridate')

                       data %>%  filter as.Date(DateTimeUTC == "2019-12-05")

I would like ALL days of 12/5/2019, including the times (hours, min and secs) Is this possible?

Upvotes: 2

Views: 105

Answers (1)

akrun
akrun

Reputation: 887981

Here, the 'DateTimeUTC' is in a different format. Convert the column to DateTime class (it seems that the format is month-day-year-hour-minute-second), and remove the time with as.Date, then do the comparison (==)

library(dplyr)
library(lubridate)
data %>%
     filter(as.Date(mdy_hms(DateTimeUTC)) ==   "2019-12-05")
#  ID           DateTimeUTC
#1  B 12/5/2019 11:30:30 PM
#2  B 12/5/2019 11:30:30 PM
#3  B 12/5/2019 11:30:30 PM

In the OP's code, the as.Date is applied on a logical vector which would be anyway FALSE because it is comparing the original format with a different format and this would result in failure of executing the code i.e.

"12/4/2019 11:30:30 PM" == "2019-12-05"
#[1] FALSE

Wrapping as.Date on this would result in an error

as.Date("12/4/2019 11:30:30 PM" == "2019-12-05")

Error in as.Date.default("12/4/2019 11:30:30 PM" == "2019-12-05") :
do not know how to convert '"12/4/2019 11:30:30 PM" == "2019-12-05"' to class “Date”

data

data <- structure(list(ID = c("A", "A", "B", "B", "B"), 
   DateTimeUTC = c("12/4/2019 11:30:30 PM", 
"12/4/2019 11:30:30 PM", "12/5/2019 11:30:30 PM", "12/5/2019 11:30:30 PM", 
"12/5/2019 11:30:30 PM")), class = "data.frame", row.names = c(NA, 
-5L))

Upvotes: 4

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