Organize models for model selection or model-averaged prediction.

fitList(..., fits)

Arguments

...

Fitted models. Preferrably named.

fits

An alternative way of providing the models. A (preferrably named) list of fitted models.

Note

Two requirements exist to conduct AIC-based model-selection and model-averaging in unmarked. First, the data objects (ie, unmarkedFrames) must be identical among fitted models. Second, the response matrix must be identical among fitted models after missing values have been removed. This means that if a response value was removed in one model due to missingness, it needs to be removed from all models.

Author

Richard Chandler rbchan@uga.edu

Examples

data(linetran) (dbreaksLine <- c(0, 5, 10, 15, 20))
#> [1] 0 5 10 15 20
lengths <- linetran$Length * 1000 ltUMF <- with(linetran, { unmarkedFrameDS(y = cbind(dc1, dc2, dc3, dc4), siteCovs = data.frame(Length, area, habitat), dist.breaks = dbreaksLine, tlength = lengths, survey = "line", unitsIn = "m") }) fm1 <- distsamp(~ 1 ~1, ltUMF) fm2 <- distsamp(~ area ~1, ltUMF) fm3 <- distsamp( ~ 1 ~area, ltUMF) ## Two methods of creating an unmarkedFitList using fitList() # Method 1 fmList <- fitList(Null=fm1, .area=fm2, area.=fm3) # Method 2. Note that the arugment name "fits" must be included in call. models <- list(Null=fm1, .area=fm2, area.=fm3) fmList <- fitList(fits = models) # Extract coefficients and standard errors coef(fmList)
#> lam(Int) p(Int) p(area) lam(area) #> Null -0.1710554 2.386380 NA NA #> .area -0.1678270 3.002507 -0.120364 NA #> area. 0.2364320 2.386386 NA -0.08005895
SE(fmList)
#> lam(Int) p(Int) p(area) lam(area) #> Null 0.1337819 0.1273598 NA NA #> .area 0.1340212 0.5401575 0.09548038 NA #> area. 0.5122837 0.1273614 NA 0.0979427
# Model-averaged prediction predict(fmList, type="state")
#> Predicted SE lower upper #> 1 0.8312132 0.1182056 0.6325438 1.092772 #> 2 0.8524076 0.1169823 0.6528972 1.112951 #> 3 0.8331920 0.1166589 0.6358157 1.092103 #> 4 0.8315502 0.1179278 0.6331133 1.092628 #> 5 0.8444727 0.1130560 0.6495892 1.097823 #> 6 0.8628921 0.1284214 0.6509868 1.145233 #> 7 0.8625919 0.1280257 0.6511054 1.144148 #> 8 0.8271520 0.1219457 0.6253753 1.095368 #> 9 0.8195735 0.1303255 0.6112124 1.103804 #> 10 0.8555768 0.1198427 0.6529052 1.121399 #> 11 0.8164013 0.1341851 0.6052469 1.108477 #> 12 0.8488432 0.1145846 0.6520535 1.105031
# Model selection modSel(fmList, nullmod="Null")
#> nPars AIC delta AICwt cumltvWt Rsq #> Null 2 164.75 0.00 0.43 0.43 0.000 #> .area 3 165.18 0.43 0.35 0.78 0.122 #> area. 3 166.08 1.32 0.22 1.00 0.055