Get the distance between patches — atl_patch

Gets the linear distance between the first point of patch i and the last point of the previous patch patch i - 1. Distance is returned in metres. This function is used internally by other functions, and rarely on its own.

Usage

atl_patch_dist(
  data,
  x1 = "x_end",
  x2 = "x_start",
  y1 = "y_end",
  y2 = "y_start"
)

Arguments

data: A dataframe of or extending the class data.frame, such as a data.table. This must contain two pairs of coordinates, the start and end X and Y coordinates of a feature.
x1: The first X coordinate or longitude; for inter-patch distances, this is the last coordinate (x_end) of a patch \(i\).
x2: The second X coordinate; for inter-patch distances, this is the first coordinate (x_start) of a subsequent patch \(i + 1\).
y1: The first Y coordinate or latitude; for inter-patch distances, this is the last coordinate (y_end) of a patch \(i\).
y2: The second Y coordinate; for inter-patch distances, this is the first coordinate (y_start) of a subsequent patch \(i + 1\).

Value

A numeric vector of the length of the number of patches, or rows in the input dataframe. For single patches, returns NA. The vector has as its elements NA, followed by n-1 distances, where n is the number of rows.

Author

Pratik R. Gupte

Examples

# basic usage of atl_patch_dist
if (FALSE) { # \dontrun{
atl_patch_dist(
  data = data,
  x1 = "x_end", x2 = "x_start",
  y1 = "y_end", y2 = "y_start"
)
} # }