I am trying to perform an nls for a valid negative exponential function: zz=nls(y~constant+a.est*2.7183^(b.est*x),start=list(constant=4.0,a.est=-4,b.est = -.005),trace=T)
and am getting a number of different error messages, the most problematic of which is "Error in nls(ring.area ~ constant + a.est * 2.7183^(b.est * ba.beg), start = list(constant = 4, : REAL() can only be applied to a 'numeric', not a 'logical'" I can't see where there are any "logicals" in this equation to cause this problem. Any help appreciated. Thank you. Jim Bouldin ______________________________________________ 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.
