Thank you Jorge and Florent for your responses. Now, I 'd like to get the date *(and its index) *where myvalue < 2000 for the first time. I expect for a result like (index, date) = (3, 2012-01-07 )
This way does not work: ind = match(df$myvalue <2000, df$myvalue) res = df$DateTime[ind] -- View this message in context: http://r.789695.n4.nabble.com/dataframe-how-to-select-an-element-from-a-row-tp4311881p4312847.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
