Can you provide a reference or link to the document? I think that you have a misprint or a typo in it.
the na.omit is a reference to missing data that is accounted for in the vector, which would appear as NA in the data. For example this works just fine for me conc = c(0, 10, 20, 30, 40, 50) signal = c (4, 22, 44, 60, 82, NA) lm( signal ~ conc) as does this conc = c(0, 10, 20, 30, 40, 50) signal = c (NA, 4, 22, 44, 60, 82) lm( signal ~ conc) but they give very different results. I don't think R has changed ----someone just make typing mistake. John Kane Kingston ON Canada > -----Original Message----- > From: tesara...@gmail.com > Sent: Fri, 9 Nov 2012 08:37:13 -0800 (PST) > To: r-help@r-project.org > Subject: [R] lm function - strange error > > I am following a document teaching how to use regression and right at the > onset I get an R error. I understand that variables "conc" and "signal" > should have the same length but I am using the what R manual suggests to > drop the error and it is not cooperating. What gives? The manual says > that the default is na.ombit by the way, not that it's addition does > anything > > How do I make it omit the extra items? I want to follow this document > but > it seems that R has changed since that one was written > > Here is the code > > conc = c(0 10 20 30 40 50) > signal = c (4, 22, 44, 60, 82) > lm( signal ~ conc) > > #Error in model.frame.default(formula = signal ~ conc, drop.unused.levels > = > TRUE) : > #variable lengths differ (found for 'conc') > > > lm (conc~signal, na.action=na.omit) > #Error in model.frame.default(formula = conc ~ signal, na.action = > na.omit, > : > #variable lengths differ (found for 'signal') > > > lm (conc~signal, na.action=na.exclude) > #Error in model.frame.default(formula = conc ~ signal, na.action = > na.exclude, : > #variable lengths differ (found for 'signal') > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/lm-function-strange-error-tp4649065.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. ____________________________________________________________ FREE 3D EARTH SCREENSAVER - Watch the Earth right on your desktop! ______________________________________________ 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.
