# areaEstimator: Area Estimator In DIGSS: Determination of Intervals Using Georeferenced Survey Simulation

## Description

Estimate the area of multiple overlapping ellipses

## Usage

 `1` ```areaEstimator(sitemap, fieldarea, precision = 1000) ```

## Arguments

 `sitemap` a matrix with sites per row and columns: `site_number`, `site_area`, `eccentricity`, `angle`, `center.x`, `center.y`, `ellipse.a`,`ellipse.b` `fieldarea` vector with dimensions of field surveyed in km: `c(x_size,y_size)` `precision` how many dots will be projected of field. Total dots equal `precision * precision`. Default value = `1000` (1 million dots projected)

## 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 cookie-cutter 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

 ```1 2 3 4 5 6 7 8``` ``` #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) ```

DIGSS documentation built on Aug. 4, 2021, 5:06 p.m.