search for: internalpars

Hi! How to write in model's formula of type: nls(y~k/(x^n), data=data, start=list(k=1,n=1)) i.e the problem is on x^n, I(x^n) generate error thanks Jarek

This might be an easy question. I tried to catch the results of nls, but to no avail. For example, if I try to fit a modle y~A*x*x+B*x+C nls will print out what A, B, and C, but how can I store these numbers to a different variable so that I can make use of them? I tried to "unclass" the result of nls, but couldn't see any of the parameters. Y C Tao

...f.obs and x.obs) nls.emp <- nls(f.obs ~ 1-(a+1)*b^x.obs/(a+b^x.obs), data= data, start=list(a = -.9871731343, b = 51.78568669), trace=TRUE, algorithm = "port") But it just returns 0: 15.777046: -0.987173 51.7857 Error in numericDeriv(form[[3]], names(ind), env, ifelse(internalPars < : Missing value or an infinity produced when evaluating the model My initial values is calculated in maple in a nonlinear equation system. I used f(0.05) and f(0.5). Thanks, J