prepRing {dwp}

Format a Search Layout into Rings for Analysis

Description

A function for creating a characterization of the search plot at each turbine by rings. The ground around each turbine is divided into 1 meter concentric rings out to the limit of the search plot. The amount of area searched in each ring and search class (if a search class column is present in the data) at each turbine is calculated, along with the fraction of area searched in each ring. In addition, sum totals of the area in each ring and the average fraction of the area searched in each ring across all turbines at the site are tallied as well. This is a convenient structure for the Poisson regressions that are used to estimate the carcass distributions with respect to distance from the turbines, the probabilities of carcasses landing in the searched areas, and the fraction of carcasses in the searched area.

Usage

prepRing(x, ...)

## S3 method for class 'shapeLayout'
prepRing(x, scVar = NULL, notSearched = NULL, silent = FALSE, ...)

## S3 method for class 'simpleLayout'
prepRing(x, ...)

## S3 method for class 'numeric'
prepRing(x, srad, ...)

## S3 method for class 'polygonLayout'
prepRing(x, ...)

Arguments

x

a search plot layout as imported and processed by initLayout into a shapeLayout, polygonLayout, or simpleLayout object, or a bare vector of carcass distances if search plots are all circular with the same radius and no unsearched area within the search radius.

...

ignored

scVar

name of the search class variable (optional), a column in the shape file for the search polygons. scVar is ignored if x is not a shapeLayout object.

notSearched

name of the search class(es) in scVar that represent unsearched areas. Applicable only if x is a shapeLayout object and scVar is provided. Polygons associated with scVar values in notSearched are not included in the rings characterization of the site. Also, turbines with no polygons that are not notSearched are not included in the rings.

silent

Processing shape files into rings may take several minutes. By default, prepRing prints periodic notice of the progress of the calculations for shape files. To suppress these notices, use silent = TRUE.

srad

search radius for data when x = bare vector of carcass observation distances.

Value

an object of class rings, which is a list with components

$rdat

list of data frames giving the area searched ("exposure"), in a 1 meter ring with outer radius "r" and the number of carcasses found "ncarc" in each ring, with search class scVar optional. There is also a summary data frame $rdat[["total"]] that sums the exposures and carcass counts for all turbines across the site. The $rdat[["total"]] is the data frame used in fitting the GLMs.

$rpA

list of data frames giving the proportion of area included in the searches ("pinc") in each ring ("r"). and the number of carcasses found "ncarc" in each ring, with search class scVar optional. There is also a summary data frame that sums the exposures and carcass counts for all turbines across the site. The $rpA data frames are used in estimating the probability of carcasses falling in the searched area at each turbine, which, in turn is used for calculating dwp

$srad

the maximum search radius at any of the turbines

$ncarc

vector of the number of carcasses at each turbine with names equal to the turbine names.

$scVar

name of the search class variable(s) or NULL

$tcenter

locations of turbine centers (nturb x 2 matrix) with UTMs of turbine locations. Column names are X and Y. Row names are the names of the turbines.