Sorry but I don't understand what your opinion. "Also try this initial values : ( 0.5, 0.5, 0.5, 1 ,1,1,1,1,1,1) Then I got same error. Regards, Serdar -- View this message in context: http://r.789695.n4.nabble.com/Optimx-Package-Error-tp4645669p4645673.html Sent from the R help mailing list archive at Nabble.com.