sharx (version 1.0-6)

hsarx: Fit SAR, SARX, HSAR and HSARX models to data

Description

Fit SAR, SARX, HSAR and HSARX models to data as described in Solymos and Lele (2012).

Usage

hsarx(formula, data, n.clones, cl = NULL, ...)

Value

An S4 object object of class 'hsarx'. It inherits from 'dcMle', and has additional slots for storing the data.

Arguments

formula

Formula.

data

Data.

n.clones

Number of clones to be used.

cl

Cluster object for parallel computations.

...

Other arguments for MCMC.

Author

Peter Solymos

Details

Fit SAR, SARX, HSAR and HSARX models to data as described in Solymos and Lele (2012).

References

Solymos, P. and Lele, S. R., 2012. Global pattern and local variation in species-area relationships. Global Ecology and Biogeography 21, 109--120.

See Also

sardata for data sets.

Examples

if (FALSE) {
## to reproduce results from Solymos and Lele (Table 1)
data(sardata)
DAT <- data.frame(sardata$islands, 
    sardata$studies[match(sardata$islands$study, 
    rownames(sardata$studies)),])
x <- hsarx(log(S+0.5) ~ log(A) | (taxon.group + island.type + 
    abs(latitude) + I(log(extent)))^2 | study, DAT, 
    n.clones=5, n.adapt=2000, n.update=3000, n.iter=1000)

## SAR
DATS <- DAT[1:191,]
(x1 <- hsarx(log(S+0.5) ~ log(A), 
    DATS[DATS$study=="abbott1978bird",], n.clones=2))

## SARX
DATS$rnd <- rnorm(nrow(DATS), log(DATS$extent))
(x2 <- hsarx(log(S+0.5) ~ log(A) * rnd, 
    DATS[DATS$study=="abbott1978bird",], n.clones=2))

## HSAR
(x3 <- hsarx(log(S+0.5) ~ log(A) | 1 | study, 
    DATS, n.clones=2, n.iter=1000))

## HSARX
(x4 <- hsarx(log(S+0.5) ~ log(A) | abs(latitude) | study, 
    DATS, n.clones=2, n.iter=1000))
}