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.
prepRing(x, ...)# S3 method for shapeLayout
prepRing(x, scVar = NULL, notSearched = NULL, silent = FALSE, ...)
# S3 method for simpleLayout
prepRing(x, ...)
# S3 method for numeric
prepRing(x, srad, ...)
# S3 method for polygonLayout
prepRing(x, ...)
an object of class rings, which is a list with components
$rdatlist 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.
$rpAlist 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
$sradthe maximum search radius at any of the turbines
$ncarcvector of the number of carcasses at each turbine with names equal to the turbine names.
$scVarname of the search class variable(s) or NULL
$tcenterlocations 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.
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
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.
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.
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.
search radius for data when x = bare vector of carcass
observation distances.