# time series plot

Can we draw time series plot with only month and year in R? I don't have date variable in my dataset.

Dataset looks like this-

month  year     percentage
1      2012      34%
2      2012      55%
.
.
.
.
1     2013      15%


I would convert it to a date column using paste and as.Date setting it to the first of the month.

> df <- data.frame('month'=c(1,2,3,1,2), year=c(2012, 2012, 2012, 2013, 2013))

> df
month year
1     1 2012
2     2 2012
3     3 2012
4     1 2013
5     2 2013

> df[, 'date_col'] <- as.Date(paste(1, df$month, df$year), '%d %m %Y')

> df
month year   date_col
1     1 2012 2012-01-01
2     2 2012 2012-02-01
3     3 2012 2012-03-01
4     1 2013 2013-01-01
5     2 2013 2013-02-01


EDIT: If you don't want first of the month as a place holder, you can use as.yearmon from the zoo package

> as.yearmon(paste(df$month, df$year), '%m %Y')
[1] "Jan 2012" "Feb 2012" "Mar 2012" "Jan 2013" "Feb 2013"

• Thank you for the reply. So you are taking date as 1 for each month. But for the present data, its said that there are 4 services .first service started somewhere in Jan, second service somewhere in May and so on..Then I cannot take 1st as date. Can we just include month and year? Mar 18, 2016 at 16:58
• I would highly recommend setting the day as a place holder even if its not exact, but if you use the zoo package you can use as.yearmon. Here is an example. stackoverflow.com/questions/10446833/…
– dmb
Mar 18, 2016 at 17:21