Tena koe Robert Many times in R one can do things without a loop. In this case, see ?rle. You might also need to check substring or months depending on how you dates are stored.
HTH .... Peter Alspach -----Original Message----- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Robert Sherry Sent: Wednesday, 4 November 2015 1:27 p.m. To: r-help@r-project.org Subject: [R] Working with Data Frames I have created what I believe to be a data frame. It is called env1$SPY. The r statement head( env1$SPY ) produces the following output: SPY.Open SPY.High SPY.Low SPY.Close SPY.Volume SPY.Adjusted 1995-01-03 45.7031 45.8437 45.6875 45.7812 324300 31.55312 1995-01-04 45.9843 46.0000 45.7500 46.0000 351800 31.70392 1995-01-05 46.0312 46.1093 45.9531 46.0000 89800 31.70392 1995-01-06 46.0937 46.2500 45.9062 46.0468 448400 31.73617 1995-01-09 46.0312 46.0937 46.0000 46.0937 36800 31.76850 1995-01-10 46.2031 46.3906 46.1406 46.1406 229800 31.80082 The above data from was created by the following commands: library( quantmod ) env1 <- new.env() getSymbols("SPY", src = 'yahoo', from = '1995-01-01', env = env1, auto.assign = T) Now, what I want to do is to loo through the data look for when the month changes. What is the proper way of writing a for loop in R and access the date field? Bob ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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. The contents of this e-mail are confidential and may be ...{{dropped:14}} ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
