Hint: x1 <- rep(pi, 283) y1 <- rnorm(283) summary(lm(y1 ~ x1))
More generally, see ?alias. The idea of singularity is a linear model is a statistical one, so it may be time to revisit your statistical education or read a good book on the subject (MASS comes to mind in this context). On Thu, 14 Feb 2008, Martin Waller wrote: > Hello, > > I'm doing an lm(y1~x1), no NAs in them, both of length 283. > > I get out however and 'NA' for the estimate of x1 and summary gives: > > Residuals: > Min 1Q Median 3Q Max > -0.1998309 -0.0447269 -0.0006252 0.0390933 0.3141687 > > Coefficients: (1 not defined because of singularities) > Estimate Std. Error t value Pr(>|t|) > (Intercept) -0.021291 0.003994 -5.331 2.01e-07 *** > x1 NA NA NA NA > --- > Signif. codes: 0 .***. 0.001 .**. 0.01 .*. 0.05 '.' 0.1 ' ' 1 > > Residual standard error: 0.06719 on 282 degrees of freedom > > > I don't understand why x1 can't be defined because of singularities - is > it trying to tell me something about the data and what can I do about it? > > Thanks for any help, > > Martin > > ______________________________________________ > 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. > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ 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.
