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