What am I failing to understand here?
The script below works fine if the dataset being used is DNase1 <- DNase[ DNase$Run == 1, ] per the example given in help(nlrob). Obviously, I am trying to understand how to use nls and nlrob to fit curves to data using R. #package=DAAG attach(codling) plot(pobs~dose) #next command returns 'step factor reduced below min factor error' m.nls <- nls( pobs ~ a/(1 + exp(( b - log(dose) )/c ) ), data = codling, start = list( a = 3, b = 0, c = 1 ), trace = TRUE ) s<-seq(min(pobs), max(pobs), .01) p.nls<-predict(m.nls,list(pobs=s)) lines(s,p.nls,col='blue') #generates 'x and y lengths differ' error Gregory A. Graves, Lead Scientist Everglades REstoration COoordination and VERification (RECOVER) Restoration Sciences Department South Florida Water Management District Phones: DESK: 561 / 682 - 2429 CELL: 561 / 719 - 8157 [[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.