dear r-experts---I have scrounged around in google (searching r-help) for the really obvious, but failed. could someone please point me to whatever function computes the standard error of a linear combination of the coefficients?
m=lm( y ~ x1 + x2 + x3 ); t.stat= (coef(m)[2]+coef(m)[3])) / mystery.function( m, x2 + x3 ); obviously, this does not work, but hopefully explains my intent. quick pointer appreciated. regards, /iaw ______________________________________________ [email protected] 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.
