Question

I have a current DataFrame that looks like this:

      DATETIME MEAS_AVG TARG_MIN TARG_AVG TARG_MAX DESPORT_NOTE
1  2012/04/10 14:03:37   0.2888     0.22     0.25     0.27      GOOD_PT
2  2012/03/30 07:48:17   0.2544     0.22     0.25     0.27      GOOD_PT
3  2012/03/24 19:23:08   0.2333     0.22     0.25     0.27      GOOD_PT
4  2012/03/25 16:10:17   0.2111     0.22     0.25     0.27      GOOD_PT
5  2012/04/10 00:58:29   0.2222     0.22     0.25     0.27      GOOD_PT
6  2012/04/14 18:32:52   0.2888     0.22     0.25     0.27      GOOD_PT
7  2012/04/21 14:47:47   0.2777     0.22     0.25     0.27      GOOD_PT

The data frame is called df3 and the specific column I am looking to replace the dates for are df3$DATETIME.

I have this function in my code already in order to strip the datetime:

date <- strptime(df3$DATETIME, "%Y/%m/%d %H:%M:%S")

All I am looking to replace all the datetime information with simple month names. This is what it should look like after the replace function:

      DATETIME MEAS_AVG TARG_MIN TARG_AVG TARG_MAX DESPORT_NOTE
1  April   0.2888     0.22     0.25     0.27      GOOD_PT
2  March   0.2544     0.22     0.25     0.27      GOOD_PT
3  March   0.2333     0.22     0.25     0.27      GOOD_PT
4  March   0.2111     0.22     0.25     0.27      GOOD_PT
5  April   0.2222     0.22     0.25     0.27      GOOD_PT
6  April   0.2888     0.22     0.25     0.27      GOOD_PT
7  April   0.2777     0.22     0.25     0.27      GOOD_PT

I am been looking all over for a simple replace column function, but can’t seem to find it. I know that I can use the as.Date() function with the formated %B to return the unabreviated month. The only problem is I do not know how to use this to replace the column values already existing.

I can list the months using this function:

list(month=months(as.Date(df3$DATETIME)))

Answer 1

df3$DATETIME <- months(as.Date(df3$DATETIME))