search for: ssfol

...nctions in stats using the following predicate that returns TRUE for any function whose first argument is called "link". is.family <- function(object) is.function(object) && identical(names(as.list(object))[1], "link") It threw an error when applied to SSfol > is.family(SSfol) Error in as.vector(x, "list") : cannot coerce type 'closure' to vector of type 'list' but works when I unclass SSfol > is.family(unclass(SSfol)) [1] FALSE It looks like as.list fails on any function that is assigned a class: &g...

A couple of weeks ago there was a question regarding apparent convergence in nls when using the SSfol selfStart model for fitting a first-order pharmacokinetic model. I can't manage to find the original message either in my archive or in the list archives but the data were time conc dose 0.50 5.40 1 0.75 11.10 1 1.00 8.40 1 1.25 13.80 1 1.50 15.50 1 1....

...1.75 18.00 1 2.00 17.00 1 2.50 13.90 1 3.00 11.20 1 3.50 9.90 1 4.00 4.70 1 5.00 5.00 1 6.00 1.90 1 7.00 1.90 1 9.00 1.10 1 12.00 0.95 1 14.00 0.46 1 24.00 NA 1 30.00 NA 1 36.00 NA 1 I use the self-starting function SSfol: nls(conc~SSfol(dose,time,lKe,lKa,lCl),data=test,trace=T,control=nls.control(maxiter=13,tol=0.001,minFactor=1.E-500),na.action=na.omit) This gives the following output: 99.15824 : -1.2061792 0.1296157 -4.3020997 86.07567 : -0.7053265 -0.3873204 -4.1278009 85.19743 : -0.5548499 -0.5333776 -...

Dear listers, I am trying to fit a model using nlsList() using alternately a SSfol() selfstart function or its developped equivalent formulae. This preliminary trial works well mydata<-groupedData(Conc~Tps|Organ,data=mydata) mymod1<-nls(Conc~SSfol(Dose,Tps,lKe,lKa,lCl),data=mydata) as well as a developped form: mymod2<-nls(Conc~Dose * exp(lKe+lKa-lCl) * (exp(-exp(l...

Dear all, I am trying to gain some experience with the function gnls from the nlme package. I tried to model the Theophyline data by trying to model the presumed dependency of the clearance on the body weight. This is my function call of gnls: gnls(conc~SSfol(Dose,Time,lKe,lKa,lCl),data=Theoph, params=list(lKe~1,lKa~1,lCl~Wt),start=c(-2.4,0.46,-3.22,0.01)) That's been the result: Error in as.vector(x, mode) : cannot coerce to vector I tried various other calls with no success. Does anyone have a hint for me? Thanks a lot Peter -.-.-.-.-.-.-.-.-...

...ight) I looked in R for functions that support the use of the matrix exponential method. Until now I used for a similar (but simpler) problem the nls package and fitted against the the parameterized solution function. But this works only for simple kinetics. The algorithms in the nls package (e.g. SSfol) work on "closed forms" of the solution function, too. My question is: Are there examples or functions in R that show the usage of the matrix exponential method or do I have to build the steps from primitive functions myself, e.g. following the recipe in Jennrich/Bright (or is there eve...

Hi, I'm trying to teach myself R, and by the way, re-learning statistics using Crawley's "Statistics: an introduction using R". I've reached the regression chapter, and when it deals with non-linear regresion using the nls library I face the following problem: I follow the steps--- >deer<-read.table("c:\\temp\\jaws.txt",header=T) ---data available at

...nls/R-ex/SSasymp.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/SSasympOff.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/SSasympOrig.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/SSbiexp.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/SSfol.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/SSfpl.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/SSlogis.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/SSmicmen.R action: create D: file: /usr/local/lib/R/library/nls/R-ex/asOneSidedFormula.R acti...

...html latex example SSasymp text html latex example SSasympOff text html latex example SSasympOrig text html latex example SSbiexp text html latex example SSfol text html latex example SSfpl text html latex example SSgompertz text html latex example SSlogis text html latex example SSmicmen...