areaEstimator {DIGSS}  R Documentation 
Area Estimator
Description
Estimate the area of multiple overlapping ellipses
Usage
areaEstimator(sitemap, fieldarea, precision = 1000)
Arguments
sitemap 
a matrix with sites per row and columns:

fieldarea 
vector with dimensions of field surveyed in km: 
precision 
how many dots will be projected of field. Total dots equal 
Details
This function will estimate the area occupied by sites (ellipses) in a rectangular
field, taking into consideration the fact that sites can overlap. It is formatted to be used inside
fieldMap()
.
This function is a cookiecutter area estimator, given the complexities of calculating the real areas of overlapping ellipses. It projects N x N equally spaced dots in the survey field and calculates the ratio of how many of them fall inside at least one site (ellipse). Using a precision of 1000 x 1000 dots, it approximates area to within 0.1% of real area.
Value
The rate of points that are inside at least one ellipse divided by all points projected in the area.
Examples
#create a matrix with 2 sites randomly located using `fieldMap()`
site.example<fieldMap(c(1,1),2,250000,plot=TRUE)
#define size of field
field.area<c(1,1)
#calculate area
areaEstimator(site.example$site.frame,field.area)