I am trying to compare Vbert growth curves from several years of fish data. I
am following the code provided by:
http://www.ncfaculty.net/dogle/fishR/gnrlex/VonBertalanffy/VonBertalanffy.pdf.
Specifically the section on VBGM Comparisons between groups.
This code is pretty cut and dry. I am able to run it perfectly with the "fake"
data that is provided. But when I run it with my own data I get stuck with this
line:
fitGen <- nls(vbGen,data=LMB,start=svGen)
I get this error code: Error in numericDeriv(form[[3L]], names(ind), env) :
Missing value or an infinity produced when evaluating the model.
Does anyone know how to fix it? I have no missing values and do not know how to
fix the infinity produced.
Here is my data set: structure(list(Age = c(1L, 2L, 3L, 5L, 1L, 2L, 3L, 4L, 1L,
2L, 3L, 4L, 1L, 2L, 3L, 4L, 5L, 1L, 2L, 3L, 4L, 5L, 1L, 2L, 3L, 4L, 5L, 1L, 2L,
3L, 4L, 5L, 1L, 2L, 3L, 4L, 5L), MM = c(155.79, 296.37, 325.77, 374.65, 181.46,
258.31, 321.88, 355.6, 139.75, 230.72, 319.61, 344.84, 130.92, 236.34, 290.53,
360.33, 400.61, 155.33, 240.87, 315.46, 345.05, 378.2, 134.71, 256.66, 333.71,
362.99, 381.46, 153.91, 217.21, 287.8, 357.28, 385.62, 222.25, 288.93, 294.05,
332.79, 367.39), Year = c(2005L, 2005L, 2005L, 2005L, 2006L, 2006L, 2006L,
2006L, 2007L, 2007L, 2007L, 2007L, 2008L, 2008L, 2008L, 2008L, 2008L, 2009L,
2009L, 2009L, 2009L, 2009L, 2010L, 2010L, 2010L, 2010L, 2010L, 2011L, 2011L,
2011L, 2011L, 2011L, 2012L, 2012L, 2012L, 2012L, 2012L)), .Names = c("Age",
"MM", "Year"), class = "data.frame", row.names = c(NA, -37L))
In case it's helpful here is all my code before this point:
str(LMB)
MMi=as.integer(MM)
Yearf=as.factor(Year)
Agei=as.integer(Age)
( svCom <- vbStarts(MMi~Agei,data=LMB))
( svGen <- lapply(svCom,rep,2) )
vbGen <- MMi~Linf[Yearf]*(1-exp(-K[Yearf]*(Age-t0[Yearf]))+error)
fitGen <- nls(vbGen,data=LMB,start=svGen)
Thank you, April
______________________________________________
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.
