hydroloom (version 1.1.2)

add_measures: Add aggregate id measures to flowlines

Description

given a set of connected flowlines that have ids and aggregate ids, adds from_aggregate_id_measure and to_aggregate_id_measure for use with index_points_to_lines

Aggregate ids, such as mainstem ids or reachcodes span multiple flowlines. Linear referencing along these features requires knowledge of the portion of the aggregate line a given flowline makes up. This function assumes that the complete aggregate feature is included and calculates the measure of the top and bottom of each flowline along each aggregate line.

Usage

add_measures(x)
# S3 method for data.frame
add_measures(x)
# S3 method for hy
add_measures(x)

Value

x with aggregate measures added to it

Arguments

x

sf data.frame compatible with hydroloom_names with at least id and aggregate_id attributes. A pre-populated toid attribute will be used if present.

Details

If no "toid" attribute is included, make_attribute_topology is used to to create one. This is required to ensure the flowlines making up each aggregate line are sorted in a known upstream to downstream order.

This function assumes that all flowlines that make up an aggregate feature are included. Returned measures will be incomplete and incorrect if aggregate features (mainstems of reaches) are truncated.

Examples

g <- sf::read_sf(system.file("extdata/new_hope.gpkg", package = "hydroloom"))

d <- dplyr::select(g, COMID, REACHCODE) |>
  sf::st_cast("LINESTRING")

add_measures(d)