Hello, Is there a clearcut answer as to why R prints 'NA' sometimes instead of standard errors?
mle2(minuslogl = nlikfun4, start = list(a = 1, c = 1, d = 0.2, b = 0.1, b1 = 0.1), method = "Nelder-Mead") Coefficients: Estimate Std. Error z value Pr(z) a 3.83845751 0.47320236 8.1117 4.993e-16 *** c 0.95545367 NA NA NA d -0.22509015 NA NA NA b 0.04260199 0.00743892 5.7269 1.023e-08 *** b1 0.00212538 0.00031189 6.8145 9.459e-12 *** --- regards, s [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.