I am trying to fit the 4-parameter logistic model with SSfpl. The estimation is terminated with a message "step factor 0.000488281 reduced below 'minFactor' of 0.000976562". I tried to change the minFactor with nls.control(minFactor=yy) with no apparent success. A call of nls.control() without arguments always shows the value of 0.000976562. Also the estimation terminates as previously although I tried to use control=nls.control(minFactor=yy) option. Is there a way to get around this or does this mean that my model is not estimable with R? I am running Debian unstable i386 and R 1.3.0. Thanks, Kari ---------------------------------------------- Kari Ruohonen Finnish Game and Fisheries Research Institute Socioeconomic and Aquaculture Research Turku Game and Fisheries Research It?inen Pitk?katu 3, 20520 Turku, Finland tel. +358-20-5751681, +358-40-5238321 (mobile) fax +358-20-5751689 http://www.rktl.fi -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._