search for: vanfemfunc

Displaying 2 results from an estimated 2 matches for "vanfemfunc".

2008 Mar 24
0
Error using augPred with nlme grouped data
..., y="(kg)")) Under the grouping factor "name", this is a character column with 12 levels (i.e. 12 animals that I have collected "mass" from over their "age.years", both numeric columns). I create my nlsList object for the vonBertelanffy growth curve using: vanfemfunc<-function(age.years, A, lk, t0) A*((1-exp(-exp(lk)*(age.years-t0)))^3) vf.list<-nlsList(mass~vanfemfunc(age.years, A, lk, t0), data=vanfem, start=c("A"=201.8, "lk"=-1.17, "t0"=-2.71)) and then my nlme with: vf.nlme1<-nlme(vf.list) Following the methods of P...
2008 Feb 11
0
Memory allocation problem with large dataset
...problem. I am using R 2.6.1, and I have had similar problems in S-plus. My dataset is mass growth data from the same 8 animals over 10 years, and is a data.frame with 23,598 rows and 5 columns, and using object.size(data)= 664448 bytes. My first model, using the VonBertalanffy growth function: vanfemfunc<-function(age.years, A, lk, t0) A*((1-exp(-exp(lk)*(age.years-t0)))^3) vanfemfit1<-nlme(model=mass~vanfemfunc(age.years, A, lk, t0), data=vanfem, fixed=A+lk+t0~1, start=c("A"=201.8, "lk"=-1.17, "t0"=-2.71)) This fits fine, and has an object size of 3605660 byte...