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

Description Usage Format Details Source References Examples

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

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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.

Source

http://www.pwrc.usgs.gov/bbs/RawData/Choose-Method.cfm

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

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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)

rbchan/maxlike documentation built on Nov. 19, 2019, 11:56 p.m.