subset_network: Subset Network

In hydroloom: Utilities to Weave Hydrologic Fabrics

Subset Network

Description

Subsets a network to features upstream of a given outlet. For non-dendritic networks, the function identifies flowpaths connected to the upstream basin via fromnode/tonode that are not reachable by upstream navigation alone. This is useful for networks where an upstream navigation returns a basin that contains a nested basin (closed or intersecting) connected through diversions. If only_up is FALSE, those nested basins are captured by navigating downstream from missed diversions to find their outlets, then navigating upstream from those outlets.

Note: If a diversion leaves a basin entirely, the subset will include the entire basin upstream of where the diversion terminates. this function will return both closed basins and intersecting basins.

Usage

subset_network(x, outlet, only_up = FALSE)

## S3 method for class 'data.frame'
subset_network(x, outlet, only_up = FALSE)

## S3 method for class 'hy'
subset_network(x, outlet, only_up = FALSE)

## S3 method for class 'hy_topo'
subset_network(x, outlet, only_up = FALSE)

## S3 method for class 'hy_node'
subset_network(x, outlet, only_up = FALSE)

Arguments

x	data.frame network compatible with hydroloom_names.
outlet	identifier of the outlet flowpath to subset upstream from.
only_up	logical if TRUE, only upstream navigation is used and any missed diversion connections are disconnected. If FALSE (default), nested endorheic basins reachable through diversions are also included.

Details

Required attributes: id, fromnode, tonode

Conditionally: divergence (if non-dendritic)

Value

data.frame subset of x containing flowpaths upstream of the outlet.

Note: if "toid" is included in the input, it will be returned without modification. This may result in one or more "toid" entries that contain ids that are not part of the subset.

Examples

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

sub <- subset_network(x, 8893420)

nrow(sub)

hydroloom documentation built on Aug. 4, 2026, 1:07 a.m.