Thanks Steve, your explanation of the "==" is very helpful, and I will look up ?by. Ben
-----Original Message----- From: S Ellison [mailto:s.elli...@lgcgroup.com] Sent: Mon 4/23/2012 3:19 AM To: Ben Neal; r-help@r-project.org Subject: RE: Splitting a dataframe by character vector > -----Original Message----- > I am just trying to split a dataframe of 750 observations of > 29 variables by "Site", which is a vector in the dataframe > with five text names (ex. PtaCaracol). A couple of methods. i) First, look up ?split, which chops your data frame into a list of five data frames. Then use lapply on the list to get a list of summaries, or sapply to get something that will (if the results of your summary are a simple number or vector) look like an array. ii) look up ?by, which will do something like lapply (and returns a list with extra features) and will print a tidier result. > I tried "subset" .... > # Divide dataframe by Site names > Site1 <- subset(Cover, Site = "PtaCaracol") Check your syntax again; that should have been Site1 <- subset(Cover, Site == "PtaCaracol") '=' is a pairwise link or an assignment operator, not the equality test that subset would be looking for. Steve E ******************************************************************* This email and any attachments are confidential. Any use...{{dropped:8}} ______________________________________________ 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.
