nls error in formula
Anaid Diaz wrote:
Hi, I'm a new R user, with a lot of questions. At the moment I'm stoped on an error traying to fit a model:
x <- sandeel ## numeric data (2500-60000) y <- Noss ## numeric data (0-1.2) A <- 0.8 B <- 0.6 C <- 1/40000 nls( y ~ A-B*exp(-C*x))
Error in match.call(definition, call, expand.dots) :
.Primitive... is not a function
I'm not sure if the error is due to the formula sytax
or something else.
I'll appreciate any help
Sylvia
Use nls(y ~ A -B*exp(-C*x), start = c(A = 0.8, B = 0.6, C = 1/40000)) instead or, preferably, nls(y ~ SSasymp(x, Asym, R0, lrc)) and read ?SSasymp for an interpretation of the estimated parameters.