Re: [R] how to add a calculated column into a data frame

How about something like this? df <- data.frame(ID=1:3, DTVAL=c("2009-03-21","2010-05-11","2020-05-05")) df <- df %>% mutate(YEAR = as.numeric(format(as.Date(DTVAL,'%Y-%m-%d'), '%Y'))) -Original Message- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Charles Thuo Sent:

Re: [R] how to add a calculated column into a data frame

This should get you started: x <- "2009-03-21" substr( x, 1, 4 ) y <- as.integer( substr( x, 1, 4 ) ) y or yy <- as.POSIXlt( x )$year + 1900 yy RShowDoc( "R-intro" ) On June 4, 2020 9:18:00 PM PDT, Charles Thuo wrote: >Dear Sirs, > >I have a data frame that has a column that shows the transa