it doesn't appear to be a bug for me, given that one of your coefficients is NA due to linear dependencies on your design matrix.
i prefer to think of it as a feature :-) (show only the coefficients for the variables that do not show linear dependencies). x=1:5 y=c(1:3, 7, 6) fit=lm(y~x) coef(fit) coef(summary(fit)) b On Nov 12, 2006, at 11:28 PM, [EMAIL PROTECTED] wrote: > tmp <- data.frame(x=c(1,1), > y=c(1,2)) > > tmp.lm <- lm(y ~ x, data=tmp) > summary(tmp.lm) > > coef(summary(tmp.lm)) > > ## I consider this to be a bug. Since summary(tmp.lm) gives > ## two rows for the coefficients, I believe the coef() function > ## should also give two rows. > > > >> summary(tmp.lm) > > Call: > lm(formula = y ~ x, data = tmp) > > Residuals: > 1 2 > -0.5 0.5 > > Coefficients: (1 not defined because of singularities) > Estimate Std. Error t value Pr(>|t|) > (Intercept) 1.5 0.5 3 0.205 > x NA NA NA NA > > Residual standard error: 0.7071 on 1 degrees of freedom > >> coef(summary(tmp.lm)) > Estimate Std. Error t value Pr(>|t|) > (Intercept) 1.5 0.5 3 0.2048328 >> >> version > _ > platform i386-pc-mingw32 > arch i386 > os mingw32 > system i386, mingw32 > status > major 2 > minor 4.0 > year 2006 > month 10 > day 03 > svn rev 39566 > language R > version.string R version 2.4.0 (2006-10-03) >> > > > ## this is a related problem > > tmp <- data.frame(x=c(1,2), > y=c(1,2)) > > tmp.lm <- lm(y ~ x, data=tmp) > summary(tmp.lm) > > coef(summary(tmp.lm)) > > ## Here the summary() give NA for the values that can't be > ## calculated and the coef() function gives NaN. I think both > ## functions should return the same result. > > >> summary(tmp.lm) > > Call: > lm(formula = y ~ x, data = tmp) > > Residuals: > ALL 2 residuals are 0: no residual degrees of freedom! > > Coefficients: > Estimate Std. Error t value Pr(>|t|) > (Intercept) 0 NA NA NA > x 1 NA NA NA > > Residual standard error: NaN on 0 degrees of freedom > Multiple R-Squared: 1, Adjusted R-squared: NaN > F-statistic: NaN on 1 and 0 DF, p-value: NA > >> >> coef(summary(tmp.lm)) > Estimate Std. Error t value Pr(>|t|) > (Intercept) 0 NaN NaN NaN > x 1 NaN NaN NaN >> >> > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
