get_xs_point {nhdplusTools}

Get Cross Section From Point (experimental)

Description

Uses a cross section retrieval web services to retrieve a cross section given a point and specified width. Orientation is determined based on direction of a the flowline found near point. This function uses a 10m National Elevation Dataset request on the back end.

Usage

get_xs_point(point, width, num_pts)

Arguments

point

sfc POINT including crs as created by: sf::st_sfc(sf::st_point(.. ,..), crs)crs.

width

Cross section width in meters.

num_pts

numeric number of points to retrieve along the cross section.

Value

sf data.frame containing points retrieved.

Examples

point <- sf::st_sfc(sf::st_point(x = c(-105.97218, 36.17592)), crs = 4326)

(xs <- get_xs_point(point, 300, 100))

if(inherits(xs, "sf")) {

bbox <- sf::st_bbox(xs) + c(-0.005, -0.005, 0.005, 0.005)

nhdplusTools::plot_nhdplus(bbox = bbox, cache_data = FALSE)

plot(sf::st_transform(sf::st_geometry(xs), 3857), pch = ".", add = TRUE, col = "red")
plot(sf::st_transform(sf::st_sfc(point, crs = 4326), 3857), add = TRUE)

plot(xs$distance_m, xs$elevation_m)
}