nhdplusTools (version 0.7.1)

get_path_lengths: Get Path Lengths

Description

Given a network and set of IDs, finds path lengths between all identified flowpath outlets. This algorithm finds distance between outlets regardless of flow direction.

Usage

get_path_lengths(outlets, network, cores = 1, status = FALSE)

Value

data.frame containing the distance between pairs of network outlets. For a network with one terminal outlet, the data.frame will have `nrow(network)^2` rows.

Arguments

outlets

vector of IDs from data.frame

network

data.frame with ID, toID, and lengthkm attributes.

cores

integer number of cores to use for parallel computation.

status

logical print status and progress bars?

Examples

source(system.file("extdata", "walker_data.R", package = "nhdplusTools"))
fline <- walker_flowline

outlets <- c(5329303, 5329357, 5329317, 5329365, 5329435, 5329817)

# Add toCOMID
fline <- nhdplusTools::get_tocomid(fline, add = TRUE)

fl <- dplyr::select(fline, ID = comid, toID = tocomid, lengthkm)

path_lengths <- get_path_lengths(outlets, fl)

outlet_geo <- sf::st_sf(
  dplyr::left_join(data.frame(ID = outlets),
                   dplyr::select(fline, ID = comid), by = "ID"))

sf::st_geometry(outlet_geo) <- sf::st_geometry(nhdplusTools::get_node(outlet_geo))

plot(sf::st_geometry(fl))
plot(sf::st_geometry(outlet_geo), add = TRUE)