[R] Possible bug in summary of residuals with lm and weights

Frank E Harrell Jr f.harrell at vanderbilt.edu
Tue Jun 28 18:16:17 CEST 2005


I sent this to r-devel the other day but didn't get any takers.  This 
may not be a bug but rather an inconsistency.
I'm not sure if this is intentional.  summary.lm stores weighted
residuals whereas I think most users will want print.summary.lm to
summarize unweighted ones as if saying summary(resid(fit)).

> set.seed(1)
> dat <- data.frame(y = rnorm(15), x = rnorm(15), w = 1:15)
> f <- lm(y ~ x, weights = w, data = dat)
> summary(f)
. . . .
Residuals:
    Min     1Q Median     3Q    Max
-8.260 -1.565  0.117  2.105  4.666
. . . .
> resid(f)

           1           2           3           4           5           6
-0.73429677  0.06818092 -1.20558034  1.25783256  0.05231879 -1.18383039
           7           8           9          10          11          12
  0.16034166  0.59880438  0.98337588 -0.58944957  1.40690588  0.31138819
          13          14          15
-0.35111933 -2.20770335  0.89438636

> version
platform i386-pc-linux-gnu
arch     i386
os       linux-gnu
system   i386, linux-gnu
status
major    2
minor    1.0
year     2005
month    04
day      18
language R

-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University




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