maxlike (version 0.1-11)

carw: The Carolina Wren data used by Royle et al. (2012)

Description

These data come from the North American Breeding Bird Survey. They include presence-only and presence-absence data for all 25 square-kilometer covering the contiguous United States. See Royle et al. (2012) for details.

Usage

data(carw)

Format

The format is: List of 5 $ raster.data:'data.frame': 31980 obs. of 6 variables:

$ pa.data :'data.frame': 4615 obs. of 9 variables:

$ xy1 :'data.frame': 12082 obs. of 2 variables:

$ ext : num [1:4] -3043880 3106120 114746 3364746

$ dim : num [1:2] 130 246

Details

The component raster.data contains the spatially-referenced covariate data that can be coverted to a raster object. pa.data is a data.frame of presence-absence data. xy1 is a data.frame of coordinates of routes where Carolina Wrens were detected. The other components are attibutes necessary for formatting raster.data as a raster object.

References

Royle, J.A., R.B. Chandler, C. Yackulic and J. D. Nichols. 2012. Likelihood analysis of species occurrence probability from presence-only data for modelling species distributions. Methods in Ecology and Evolution. doi: 10.1111/j.2041-210X.2011.00182.x

Examples

data(carw)

# Convert data frame to a list of rasters
rl <- lapply(carw.data$raster.data, function(x) {
   m <- matrix(x, nrow=carw.data$dim[1], ncol=carw.data$dim[2],
               byrow=TRUE)
   r <- raster(m)
   extent(r) <- carw.data$ext
   r
})

# Stack and name them
rs <- stack(rl[[1]], rl[[2]], rl[[3]], rl[[4]], rl[[5]], rl[[6]])
names(rs) <- names(carw.data$raster.data)

plot(rs)