subsetting a list of dataframes
shouldKeep <- sapply(listOfDataFrames, function(df)nrow(df)>1) listOfDataFrames[shouldKeep] or, compressed to get rid of the intermediate variable listOfDataFrames[sapply(listOfDataFrames, function(df)nrow(df)>1)] If you are writing production code and there is any chance that listOfDataFrames might be an empty list you can use vapply (which requires that you supply a prototype for FUN's return value): listOfDataFrames[vapply(listOfDataFrames, function(df)nrow(df)>1, FUN.VALUE=FALSE)] Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com
-----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Lara Poplarski Sent: Tuesday, May 17, 2011 1:25 PM To: r-help at r-project.org Subject: [R] subsetting a list of dataframes Hello All, I have a list of dataframes, and I need to subset it by keeping only those dataframes in the list that meet a certain criterion. Specifically, I need to generate a second list which only includes those dataframes whose number of rows is > 1. Could someone suggest how to do this? I have come close to what I need with loops and such, but there must be a less clumsy way... Many thanks, Lara [[alternative HTML version deleted]]
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