Regression slopes
No modification needed. Fit either of lm(y-x ~ x + z) lm(y ~ x + z + offset(x)) and the t-test in the summary will be a test of the coefficient of x being one. You can also use such models to do an anova against a modle with unit coefficient.
On Thu, 5 Jun 2003, Martin Biuw wrote:
Sorry if this is an obvious one, but is there a simple way to modify the lm function to test whether a slope coefficient is significantly different from 1 instead of different from 0?
Brian D. Ripley, ripley at stats.ox.ac.uk 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