On Sep 20, 2011, at 7:37 PM, justin jarvis wrote: > That still discards the other data columns. For example, in the > data frame > > V1 V2 V3 V4 > 1 1 1 NA 1 > 2 1 NA 1 1 > 3 1 NA 1 1 > 4 1 1 1 1 > 5 1 1 1 1 > > Suppose I was running a regression using V1 and V2. R will remove > rows 2 and 3 due to the "NA." I would like a way to look at only > the observations used for the regression, the data frame: > > V1 V2 V3 V4 > 1 1 1 NA 1 > 4 1 1 1 1 > 5 1 1 1 1
The use this... dfrm[ complete.cases( subset(dfrm, select=c("V1","V2") ) , ] complete.cases() returns a lofical vector than can be used for indexing. -- David > > If I run na.omit(subset(dataframe, select= c(V1,V2)) it returns > > V1 V2 > 1 1 1 > 4 1 1 > 5 1 1 > > Sorry for being unclear the previous time. > > Justin > > On Tue, Sep 20, 2011 at 4:54 AM, David Winsemius <dwinsem...@comcast.net > > wrote: > > On Sep 19, 2011, at 8:49 PM, justin jarvis wrote: > > I have a data set with many missing observations. When I run a > regression, R of course discards the observations (the whole row) that > have "NA". I want to tabulate some baseline characteristics (column > means) but only for the observations that R used for the regression. > I tried to recreate this data frame by using na.omit on the original > data frame, but this will not work as this will discard an observation > with an "NA" in any column, and not just in the covariates. > > In summary, I only want to remove observations that have an "NA" in > the covariate columns. Something like Stata's e(sample), as far as I > > na.omit(subset(dfrm, select= <covariate-vector> ) # or equivalent > > can tell. > > Justin Jarvis > PhD student, University of California, Irvine > > ______________________________________________ > 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. > > David Winsemius, MD > West Hartford, CT > > David Winsemius, MD West Hartford, CT [[alternative HTML version deleted]] ______________________________________________ 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.