I have three different conditions: detect, discrim, sum. In each condition I measure y at two different x levels. Thus I have 6 points. Theory says that the data should obey: y ~ (x+a)/b if cond==detect y ~ (x+a)/(2*b*(1-c)) if cond==discrim y ~ (x+a)/(2*b*(1+c)) if cond==sum These are 3 lines, one per condition. I need to estimate a, b, and c. How to do it in R? (I imagine that lm() will do it somehow) Thanks very much for any help. Bill Simpson -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._