the original data are V2 =c(371000,285000 ,156000, 20600, 4420, 3870, 5500 ) T2=c( 0.3403 ,0.4181 ,0.4986 ,0.7451 ,1.0069 ,1.553) nls2=nls(V2~v0*(1-epi+epi*exp(-cl*(T2-t0))),start=list(v0=10^7,epi=0.9,cl=6.2,t0=8.7)) after execution error occurs as below ################################################################ Error in nlsModel(formula, mf, start, wts) : singular gradient matrix at initial parameter estimates Error in nlsModel(formula, mf, start, wts) : singular gradient matrix at initial parameter estimates In addition: Warning messages: 1: In lhs - rhs : longer object length is not a multiple of shorter object length 2: In .swts * attr(rhs, "gradient") : longer object length is not a multiple of shorter object length
could anyone help me ?thansks -- View this message in context: http://r.789695.n4.nabble.com/nls-problem-with-R-tp3494454p3494454.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
