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Calculation Standard Deviational Ellipse

Source: R/pp-std_dev_ellipse.R
std_dev_ellipse.Rd

From an sf object containing points, calculate the standard deviational ellipse.

Usage

std_dev_ellipse(geometry)

Arguments

geometry

an sfc object. If a polygon, uses sf::st_point_on_surface().

Value

An sf object with three columns

  • sx: major axis radius in CRS units,

  • sy: minor axis radius in CRS units,

  • theta: degree rotation of the ellipse.

sf object's geometry is the center mean point.

Details

The bulk of this function is derived from the archived CRAN package aspace version 3.2.0.

Examples

#' # Make a grid to sample from
grd <- sf::st_make_grid(n = c(1, 1), cellsize = c(100, 100), offset = c(0,0))

# sample 100 points
pnts <- sf::st_sample(grd, 100)
std_dev_ellipse(pnts)
#> Simple feature collection with 1 feature and 3 fields
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 52.84892 ymin: 51.07882 xmax: 52.84892 ymax: 51.07882
#> CRS:           NA
#>        sx       sy    theta                  geometry
#> 1 39.8631 42.98488 133.0087 POINT (52.84892 51.07882)