modSel {unmarked}R Documentation

Model selection results from an unmarkedFitList

Description

Model selection results from an unmarkedFitList

Arguments

object an object of class "unmarkedFitList" created by the function fitList
nullmod optional object storing results of null model. Only used in calculation of Nagelkerke's R-squared index

Value

A S4 object with the following slots

Estimates Matrix containing parameter estimates for each model
SE Matrix containing standard errors for model parameters
Full data.frame with formula, estimates, standard errors and model selection information. Converge is optim convergence code. CondNum is model condition number. Rsq is Nagelkerke's (1991) R-squared index, which is only returned when the nullmod argument is specified.

References

Nagelkerke, N.J.D. (2004) A Note on a General Definition of the Coefficient of Determination. Biometrika 78, pp. 691-692.

Examples

data(linetran)
(dbreaksLine <- c(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)

fl <- fitList(Null=fm1, A.=fm2, .A=fm2)
fl

(ms <- modSel(fl, nullmod=fm1))

ms@Estimates
ms@SE
ms@Full

[Package unmarked version 0.8-1 Index]