search for: noxp_04

...) and pollutant name. Names with no ?L? prefix or 01/04 suffix are lag 0. Lag 01 is average of lag 0 and 1, and 04 is average of 0 to 4 days. How can one do that in R? I will ignore the other components( e.g. 10 , max or mean) Current stand L1o3maxG10 L1o3P10 L2o3G10 noxP10 pm25S_01 comeanS_03 noxP_04 What I want to get : pollutant Lag station o3 1 G o3 1 P o3 2 G nox 0 P Pm25 01 S co 03 S nox 04 P Thanks -- View this message in context: http://r.789695.n4.nabble.com/Split-data-frame-and-create-a-new-column-tp4649683.html Sent from the R help mailing list archive at Nabble.com.