order_drainage_flowlines.RdUses sfnetworks endpoint connectivity and igraph depth-first traversal to keep branches together. The origin segment leads the list; source IDs break branch ties deterministically, without inferring a mainstem. Intended for NLDI/NHDPlus reference linework, not arbitrary extracted networks. With NULL origin, upstream means downstream-to-upstream across the whole graph; all downstream dependencies precede upstream edges. Separate branches/components have deterministic ordering, not an inferred stationing route or mainstem. No snapping, reversal, repair, geometric intersection at crossings, network completeness or scientific acceptance is inferred. Source geometry is unchanged.
order_drainage_flowlines(lines, comid = NULL, direction = "upstream",
id_column = "nhdplus_comid")CRS-defined sf LINESTRING reference features digitized downstream.
Identifier of the navigation origin, present in lines. NULL orders the whole directed network topologically in the requested direction.
"upstream" or "downstream", away from the origin.
Column containing unique source identifiers.
Data frame in browsing order with source_row (input row), source_id, navigation_order and order_status. Ordered features come first. Unreachable features (including opposite-direction candidates from earlier queries) follow in ID order with status unreached. Cycles, missing origins/identifiers and unsupported geometry return all rows as unresolved, never a fabricated order.