Hi I am looking for a efficient way to estimate all parameters in your data.frame set using a specific function: for example ln(T)=b_0 + b_1*ln(Y_i*Y_j) + b_2*ln()+ ... + etc. Thanks, Ph -- View this message in context: http://r.789695.n4.nabble.com/OLS-Estimating-tp4580055p4580055.html Sent from the R help mailing list archive at Nabble.com.