I am really new at using R and am having difficulty changing two columns into one for time. I have Months in 1-12 and years in 1999 etc. format. I am looking to change into one Date which R will recognise as a date. I tried using strptime but as I do not have a day this caused it to automatically use the current date instead - as date of the month isn't specified does this matter?
Thanks in advance
> head(tthm.data)
WSZ_Code Treatment_Code Year Month TTHM CL2_FREE BrO3 Colour PH TURB
1 2 3 1996 1 30.7 0.35 0.00030 0.75 7.4 0.055
2 6 1 1996 2 24.8 0.25 0.00055 0.75 6.9 0.200
3 7 4 1996 2 60.4 0.05 0.00055 0.75 7.1 0.055
6 5 2 1996 3 40.3 0.15 0.00140 2.00 7.7 0.055
11 4 1 1996 3 46.5 0.25 0.00055 1.90 7.4 0.150
14 2 3 1996 3 28.4 0.25 0.00055 1.80 7.4 0.055