Hello all; My question is part statistical and part R. I have performed model II major axis regression in R using both the smatr() and lmodel2() packages, but neither offers an option to statistically weight my regression. I have a vector of weights which I would like to apply to each of my regression points (x vs. y), and was hoping that someone out there could provide me with some help on this issue. I have searched on the R help pages and online with no luck. Just to provide context, I am comparing 2 random variables which have been geographically gridded so that each grid point has one x data and one y data point. I would like to weight the regression of x vs. y such that grids with larger geographic area (near the equator) get more weight than those with smaller geographic area (near the poles). My weights are already calculated. Thanks in advance, Dan. -- View this message in context: http://n4.nabble.com/model-II-major-axis-regression-tp1474711p1474711.html Sent from the R help mailing list archive at Nabble.com.