# Extract distances and surface areas from a spatial object

Source:`R/extract_spatial_information.R`

`extract_spatial_information.Rd`

This function returns a matrix of distances between locations (in kilometer) along with a vector surface areas of the locations (in square kilometer).

## Arguments

- geometry
a spatial object that can be handled by the

`sf`

package.- id
name or number of the column to use as rownames and colnames for the output distance matrix (optional, NULL by default). A vector with length equal to the number of locations can also be used.

- show_progress
a boolean indicating if a progress bar should be displayed.

## Value

A list composed of two elements. The first element is a squared matrix representing the great-circle distance (in kilometer) between locations. The second element is a vector containing the surface area of each location (in square kilometer).

## Details

The `geometry`

must be projected in a valid coordinate reference
system. It will be reprojected in degrees longitude/latitude to compute the
great-circle distances between centroids' locations with an internal function
and to compute the surface area with the function st_area from
the sf package.

## Note

The outputs are based on the locations contained in `geometry`

and
sorted in the same order. An optional `id`

can also be provided to be used as
names for the outputs.

## Author

Maxime Lenormand (maxime.lenormand@inrae.fr)