[BioC] RMA (model II) regression with lmFit

[Paolo Innocenti]

Dear list,

does anyone know if it is possible to fit a RMA (Reduced Major Axis, or 
model II) regression in limma?

The difference should basically be that it assumes error on the x as 
well, instead of just on the response variable. In other words, instead 
of minimizing the the residual on the vertical axis, it tries to 
minimize the area between x- and y- residuals.

It would be extremely helpful for me, because the line of best fit 
doesn't change when Y~X or X~Y. I would need an estimate for the slope 
of the line when I swap the variables, but with a normal regression I 
guess I can't just do 1/b.

Thanks,
paolo


-- 
Paolo Innocenti
Department of Animal Ecology, EBC
Uppsala University
Norbyvägen 18D
75236 Uppsala, Sweden