Hello, I`m a newbie to R so maybe this question is boring, but I have a large table with several empty missing values, which come out as "NA". How can i ignore them or replace them by another number? Greetings, Thomas
It depends a bit on what function you are using. For example, set.seed(1) xx <- c(NA, rnorm(10))> mean(xx)[1] NA> mean(xx, na.rm=TRUE)[1] 0.1322028 Is how you would use this to compute a mean. Harold> -----Original Message----- > From: r-help-bounces at stat.math.ethz.ch > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Thomas Preuth > Sent: Thursday, September 21, 2006 1:59 PM > To: r-help at stat.math.ethz.ch > Subject: [R] how to ignore "NA" or replace it by another value > > Hello, > > I`m a newbie to R so maybe this question is boring, but I > have a large table with several empty missing values, which > come out as "NA". How can i ignore them or replace them by > another number? > > Greetings, Thomas > > ______________________________________________ > R-help at stat.math.ethz.ch 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. >
Most R functions have arguments of the form "na.action" or "na.rm" that allow you to specify how you treat NA's. In general, it's not a good idea to replace NA's with numbers. See also ?na.omit, ?na.action. -- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA "The business of the statistician is to catalyze the scientific learning process." - George E. P. Box> -----Original Message----- > From: r-help-bounces at stat.math.ethz.ch > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Thomas Preuth > Sent: Thursday, September 21, 2006 10:59 AM > To: r-help at stat.math.ethz.ch > Subject: [R] how to ignore "NA" or replace it by another value > > Hello, > > I`m a newbie to R so maybe this question is boring, but I > have a large > table with several empty missing values, which come out as > "NA". How can > i ignore them or replace them by another number? > > Greetings, Thomas > > ______________________________________________ > R-help at stat.math.ethz.ch 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. >
On Thu, 2006-09-21 at 19:58 +0200, Thomas Preuth wrote:> Hello, > > I`m a newbie to R so maybe this question is boring, but I have a large > table with several empty missing values, which come out as "NA". How can > i ignore them or replace them by another number? > > Greetings, Thomas > > ______________________________________________ > R-help at stat.math.ethz.ch 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.Ignoring NAs depends on what functions you want to ignore them in. As for replacing NAs with another number, this will replace all NAs with 0 # some example data dat <- as.data.frame(matrix(rnorm(100), nrow = 10)) # add some NAs dat[sample(1:10, 3), sample(1:10, 3)] <- NA dat # replace missing values with 0 dat <- sapply(dat, function(x) {x[is.na(x)] <- 0; x}) dat HTH G -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% *Note new Address and Fax and Telephone numbers from 10th April 2006* %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Gavin Simpson [t] +44 (0)20 7679 0522 ECRC [f] +44 (0)20 7679 0565 UCL Department of Geography Pearson Building [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street London, UK [w] http://www.ucl.ac.uk/~ucfagls/cv/ WC1E 6BT [w] http://www.ucl.ac.uk/~ucfagls/ %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%