A coord_matrix is a matrix with two columns named "lon" and "lat" to
represent spatial point data. They are used as an intermediary when
converting some R objects to sf::sf() objects.
as_coord_matrix() can smartly convert a range of R objects to
coord_matrix. If you are a package developer and want to add support
for smartmap to your package without having to depend on the heavy sf
package, it is enough to provide an as_coord_matrix() method.
as_coord_matrix(x, ...)# S3 method for default
as_coord_matrix(x, ...)
# S3 method for numeric
as_coord_matrix(x, ...)
# S3 method for sf
as_coord_matrix(x, ...)
# S3 method for sfc_POINT
as_coord_matrix(x, ...)
# S3 method for matrix
as_coord_matrix(x, ..., loncol = guess_loncol(x), latcol = guess_latcol(x))
# S3 method for data.frame
as_coord_matrix(x, ..., loncol = guess_loncol(x), latcol = guess_latcol(x))
any of the following:
a matrix: Either a matrix with named longitude and latitude columns
or an unnamed two column matrix containing longitude and latitude
(in that order)
a data.frame with named longitude and latitude columns
an sf::sfc_POINT object
a named or unnamed numeric vector of length 2 containing a single
longitude-latitude coordinate pair
a character scalar path or URL to a shapefile or zipped shapefile
passed on to methods
character scalars. Names of the columns of
x containing longitude and latitude. The default trying guessing the
columns.
as_coord_matrix() returns a coord_matrix object: A numeric
matrix with the columns "lon"and "lat" (in that order)
https://stackoverflow.com/questions/7309121/preferred-order-of-writing-latitude-longitude-tuples