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How to combine year, month, and day column in an R data frame?
Sometimes date variable is recorded in three different columns representing year, month, and day instead of a single column as date. Therefore, we need to combine these three columns and create a single column. This can be done by using paste function and define the values with as.Date.
Consider the below data frame −
Example
Year<-sample(2001:2005,20,replace=TRUE) Month<-sample(1:12,20,replace=TRUE) Day<-sample(1:15,20,replace=TRUE) df1<-data.frame(Year,Month,Day) df1
Output
Year Month Day 1 2005 11 6 2 2003 7 1 3 2002 2 11 4 2001 2 5 5 2005 1 3 6 2001 7 14 7 2004 3 8 8 2004 1 10 9 2005 11 12 10 2002 3 9 11 2001 10 10 12 2001 7 8 13 2002 3 7 14 2004 8 4 15 2002 8 7 16 2005 4 7 17 2003 10 5 18 2002 12 13 19 2004 5 1 20 2003 3 8
Creating new column named as Date by combining Year, Month, and Day −
Example
df1$Date<-as.Date(with(df1,paste(Year,Month,Day,sep="-")),"%Y-%m-%d") df1
Output
Year Month Day Date 1 2005 11 6 2005-11-06 2 2003 7 1 2003-07-01 3 2002 2 11 2002-02-11 4 2001 2 5 2001-02-05 5 2005 1 3 2005-01-03 6 2001 7 14 2001-07-14 7 2004 3 8 2004-03-08 8 2004 1 10 2004-01-10 9 2005 11 12 2005-11-12 10 2002 3 9 2002-03-09 11 2001 10 10 2001-10-10 12 2001 7 8 2001-07-08 13 2002 3 7 2002-03-07 14 2004 8 4 2004-08-04 15 2002 8 7 2002-08-07 16 2005 4 7 2005-04-07 17 2003 10 5 2003-10-05 18 2002 12 13 2002-12-13 19 2004 5 1 2004-05-01 20 2003 3 8 2003-03-08
Let’s have a look at another example −
Example
Year<-sample(2011:2020,20,replace=TRUE) Month<-sample(1:12,20,replace=TRUE) Day<-sample(1:25,20,replace=TRUE) df2<-data.frame(Day,Month,Year) df2
Output
Day Month Year 1 14 3 2015 2 14 5 2013 3 5 10 2019 4 25 11 2011 5 21 7 2017 6 16 5 2019 7 10 2 2015 8 1 6 2012 9 13 8 2018 10 8 2 2019 11 18 7 2012 12 20 11 2018 13 19 12 2020 14 16 10 2015 15 9 3 2020 16 1 7 2017 17 10 12 2018 18 6 11 2014 19 9 6 2014 20 15 10 2019
Creating new column named as Date by combining Year, Month, and Day −
Example
df2$Date<-as.Date(with(df2,paste(Year,Month,Day,sep="-")),"%Y-%m-%d") df2
Output
Day Month Year Date 1 14 3 2015 2015-03-14 2 14 5 2013 2013-05-14 3 5 10 2019 2019-10-05 4 25 11 2011 2011-11-25 5 21 7 2017 2017-07-21 6 16 5 2019 2019-05-16 7 10 2 2015 2015-02-10 8 1 6 2012 2012-06-01 9 13 8 2018 2018-08-13 10 8 2 2019 2019-02-08 11 18 7 2012 2012-07-18 12 20 11 2018 2018-11-20 13 19 12 2020 2020-12-19 14 16 10 2015 2015-10-16 15 9 3 2020 2020-03-09 16 1 7 2017 2017-07-01 17 10 12 2018 2018-12-10 18 6 11 2014 2014-11-06 19 9 6 2014 2014-06-09 20 15 10 2019 2019-10-15
Updated on: 18-Oct-2020
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