[R] Interpreting p values of gls in nlme

Dear all I have undertaken some phylogenetic and non-phylogenetic regressions with gls() in nlme with single preictor variables. A p value is associated with the intercept (upper p value) and another with the predictor variable (lower). Which p value is important? What does it mean if the intercep

[R] AICc function with gls

Hi I get the following error when I try and get the AICc for a gls regression using qpcR: > AICc(gls1) Loading required package: nlme Error in n/(n - p - 1) : 'n' is missing My gls is like this: > gls1 Generalized least squares fit by REML Model: thercarnmax ~ therherbmax Data: NULL Log-

Re: [R] AICc function with gls

Just realized was because I had an object called AICc. On Sun, Sep 4, 2011 at 2:08 AM, Roland Sookias wrote: > Hi > > I get the following error when I try and get the AICc for a gls regression > using qpcR: > > > > AICc(gls1) > Loading required package: nlme > E

[R] nlme gls errors

Hi I keep getting an error like this: Error in `coef<-.corARMA`(`*tmp*`, value = c(18.3113452983211, -1.56626248550284, : Coefficient matrix not invertible or like this: Error in gls(archlogfl ~ co2, correlation = corARMA(p = 3)) : false convergence (8) with the gls function in nlme. The f

[R] Grofit

Hi Is it possible to use grofit to get the AIC of several (e.g. two) growth models and compare both these and model parameters? All I can get it to do so far is return parameters for a single model. Cheers Roland [[alternative HTML version deleted]]

Re: [R] Grofit

Just to say, I got this solved. On Wed, Jul 20, 2011 at 7:55 PM, Roland Sookias wrote: > Hi > > Is it possible to use grofit to get the AIC of several (e.g. two) growth > models and compare both these and model parameters? All I can get it to do > so far is return parameters for

[R] Ouch - brown, hansen error

Hi I'm trying to use ouch's hansen and brown functions but I get the error: > brown(logflatnodes,archotreeouch) Error in backsolve(l, x, k = k, upper.tri = upper.tri, transpose = transpose) : NA/NaN/Inf in foreign function call (arg 1) and with hansen also: Error in optim(par = c(sqrt.alpha

Re: [R] Ouch - brown, hansen error

Sorry, just realized I sent this to r help not r sig phylo which would probably be more appropriate. Will re-post there - do ignore this. On Mon, Jul 25, 2011 at 8:01 AM, Roland Sookias wrote: > Hi > > I'm trying to use ouch's hansen and brown functions but I get the

[R] nls - can't get published AICc and parameters

Hi I'm trying to replicate Smith et al.'s (http://www.sciencemag.org/content/330/6008/1216.abstract) findings by fitting their Gompertz and logistic models to their data (given in their supplement). I'm doing this as I want to then apply the equations to my own data. Try as a might, I can't quite

Re: [R] nls - can't get published AICc and parameters

I also see you divided the body mass by the mass at time zero - why was that? Thanks so much for trying to help. On Wed, Jul 27, 2011 at 1:08 AM, Ben Bolker wrote: > Roland Sookias gmail.com> writes: > >> >> Hi >> >> I'm trying to replicate Smith et al.&#